


a rose by any other name

by Another_Freak1258



Category: Supernatural
Genre: (Maybe?) graphic birth (idk), Angst with a Happy Ending, Bottom Sam, Dean is pretty brutal, Fluff and Angst, Hermaphrodite Sam Winchester, M/M, Minor Character Death, No underage, Omega Sam, Pregnancy Kink, Pregnant Sam Winchester, Shark Dean, Sibling Incest, Tags May Change, Teenchesters, Top Dean, Very graphic, Young Sam Winchester, at least for a hot minute, eating mermaids, lots of blood, mermaid sam, original Winchester children - Freeform
Language: English
Status: Completed
Published: 2018-06-16
Updated: 2019-04-25
Packaged: 2019-05-24 07:23:22
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 10
Words: 32,563
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14950187
Author URL: https://archiveofourown.org/users/Another_Freak1258/pseuds/Another_Freak1258
Summary: A chance meeting between a young mer named Sam and a shark named Dean—(courtesy of pretty seashells and an octo-bitch)—challenges the confines of the food chain.





	1. Chapter One

**Author's Note:**

> I love mermaid stories and I haven't found any wincest ones so I decided to write this

Since the beginning of whichever beginning you believe to have began, there were alphas, omegas, and betas. 

  


Betas, uncommon and seen as anomalies among mercolonies, were often alienated and even sometimes killed for their sex. Thankfully— although there’s still stigmas against betas in most colonies — families no longer go to that extreme when a pup presents. Or, well, has a  _lack_  of presenting.

  


Alphas and omegas have maintained the same societal value and role since prehistoric ages. Alphas are meant to be domineering, tough, and provide for their mate and brood. Omegas are meant to be pretty, shy, and homemakers. 

  


The Crag colony is more liberal than most, promoting omegas to be less dependent (but never completely  _independent_ ) and more outgoing. This is due to the fact it’s only been an official colony for a handful of decades and it was established by a merger six families who were either sick of conforming to their expected roles or desired to raise their brood in a more progressive atmosphere. It’s expanded greatly since it’s founding, much to the surprise of older colonies who expected it to be wiped out by predators years ago.

  


Crag’s attitude of ‘alphas need to cry sometimes too’ and ‘being an omega does not mean you need to sit around and wait for an alpha’ is what has led little Sam Singer to the outskirts of the colony, searching for remarkable seashells.

  


Sam Singer is an omega mer of only fourteen springs, known in Crag for being outragingly mouthy one moment before tilting his neck and blushing the next. 

  


After Sam presented as an omega a good few moons ago, he had adopted the most liberal mindset a mer of thirteen springs could have, scoffing at the mere idea of mating with an alpha and setting down into their nest (prison) and bearing their pups (parasites). But as his first year of omegahood progressed, Sam began to see the appeal of raising a brood and having a handsome alpha to wait on him. He’s much too reluctant to admit it aloud as of now, but he’s of the belief that yes, it’s okay to remain mateless and live your life independently, but it’s also okay to want to spend your life fussing over a house and doting on your alpha.

  


Sam’s anniversary of his presentation is very near, because he’s begun to experience common pre-heat symptoms such as overheating, nausea, and arousal. 

  


Traditionally, alphas are meant to gather interesting trinkets, tasty food, or beautiful shells to win the favor of a pre-heat omega. Accepting such a gift from an alpha signifies the omega’s returned interest to mate. Once said omega reaches their heat, their chosen alpha will mate with them and remain until death. 

  


It has become a recent tradition in Crag, however, to exchange gifts. Sam remembers hearing a teacher explain, “ _An alpha giving the omega a gift instills the assumption the alpha only gives and the omega only takes. When we exchange gifts it establishes a healthy relationship of both give and take_.”

  


Thus, Sam’s looking for something to give to his chosen alpha. He’s not so much put it off as he’s been very thoughtful on if he should mate or not this season. Sam’s received plenty of gifts from alphas, but picking one to spend the rest of his life with has proved extremely difficult. But he’s finally decided on a blond alpha named Jess, and he’s got to get a move on before she loses interest and courts someone else.

  


Crag is named according to it’s proximity to a sudden, rocky terrain that descends for what appears to be miles from the edge of it. It’s a dangerous place no mer is allowed to go because of not only the jagged rocks but because many predators have been spotted in that area. It’s a place many mers have snuck out to and never returned. 

  


It’s also a place where many seashells can be found.

  


Sam runs his fingers over the shoulder bag he’s brought with him before peeking inside. There are three shells inside, all vaguely nice but dull and small, along with a carefully crafted necklace. It’s a simple snails shell on a braided seagrass cord, nothing too fancy but still thoughtful. It’s Sam’s Plan B. But Jess deserves far better than a Plan B, so Sam cautiously looks down before beginning his descent.

  


There’s a path of smoothed rocks that Sam follows downward, a gentle current that caused this smoothness tickling the sides of his green tail. 

  


Just as Sam’s beginning to consider a return home, he spots a small cliff spotted with various seashells. He pumps his tail quicker, completely forgetting the omnipresent cramps he’s been having in his excitement.

  


Sam settles himself on the cliff with a smile, looking around briefly to ensure he’s alone. There’s a few unnerving cave entrances where the slope levels off and becomes the cliff he’s resting on, and immediately Sam thinks in conspiracy, ‘ _These shells are here to lure me! Something is about to pop out of one of those caves and drag me inside_!’

  


Paranoid, Sam braces as if to take off any moment, eyes darting between each entrance. Nothing happens.

  


Not feeling much better but now able to proceed, Sam picks up a shiny shell and checks to his if it’s inhabited. He’s collected three shells when his hand curls around a large one only to be pinched by whatever creature is curled up inside.

  


“Ow!” Sam exclaims rather loudly, dropping the shell. He brings up the injured finger to his mouth to nurse as the pain fades.

  


“Hello!”

  


Sam flinches as if he’s been punched, hand flying out of his mouth and to his side as he whips around and tries to identify where the voice came from (so he knows which direction to swim away from).

  


“Hey! Hello!” comes the voice again, now easier to locate because Sam was expected it. He’s once again poised to launch, shaking so bad the shells inside his bag are rattling together. “Is someone out there? Can you hear me?”

  


The voice is growing more desperate, and in fact reflects the panic Sam feels internally. And it seems to be coming from one of the cave entrances, but it’s muffled and hard to understand. 

  


“HELP!” emanates loudly as Sam’s about to leave it a mystery and return home. His instinct to flee battles his instinct to help someone in trouble. The latter wins.

  


“Hello?” Sam whispers. He takes a breath, shaking his head, and tries to find his own voice. “Hello?” 

  


“Yes! Yes, help me! I’m trapped in here!” the voice replies in relief.

  


Sam swims closer to the entrances and he spots a patch he’d first considered nothing but a rock embedded in the sand, but upon closer inspection he can see a gap towards the top of it on either side. He reluctantly approaches.

  


“Where are you?” Sam asks even though he’s pretty sure he knows the answer. 

  


“I’m — I’m trapped behind this friggin rock,” the voice answers, now much too loud. 

  


“Sh! Don’t be so loud!” Sam hisses to the rock. After looking over his shoulder for a few moments, he continues with more patience. “Sorry. I see it. I don’t want to attract predators.”

  


The voice doesn’t answer. 

  


The rock has not been placed in front of the cave entrance by natural means. A hole was very obviously dug in the sand to hold the large rock in place and prevent it from being dislodged from inside the cave. “Are you okay?” 

  


“Am I okay? Ha, yeah, I  _love_  it when an octo-bitch yanks on my tail and tries to bury me alive,” the voice snarks unhappily. Now much closer, Sam can tell it’s male and most likely someone a few springs older than him. “Can you get me out?”

  


Hands firmly gripping the rock, Sam tries to heave it upwards with no success. “I - I can try. How long have you been in there?” he asks with sympathy, abandoning his lift tactic and deciding to remove the sand around the base of the rock—it’s more of a small boulder, really.

  


Sam’s displaced a few scoops of sand when the voice answers. “Not too long, I guess. Long enough I thought this actually might be where I die, as lame as that would be.”

  


With a frown, Sam promises softly, “I’ll get you out, okay? I’m... Digging up the rock.” Approximately a minute of silence passes. “You really shouldn’t be out this far, sir. There’s predators in this area and they’ll... Well, apparently they’ll... Trap you.” 

  


The voice laughs. “You bring up a great point there. I’d hate to run into a shark or something like that, huh?” he says in a strange, knowing tone. “And don’t call me sir, kid. I’m not  _that_  old. My name’s Dean.”

  


Sam bites his tongue politely in favor of squealing, ‘I am  _not_  a kid!’ and tries to ignore how gross the sand caught underneath his nails feels. “My name is Sam.”

  


“Well, Sam, what’s your excuse for being out here?”

  


Taking a quick glance behind him, Sam answers quietly, “I’m... I was, um, collecting sea shells.”

  


“Really? Isn’t that adorable.”

  


The rock is almost prime to be lifted. Sam feels his face flush in both irritation and embarrassment. “It’s for my alpha,” he hisses indignity before taking a deep breath. “I’m going to try to move the rock again.”

  


Sam hooks his fingers underneath the rock and pulls it towards the empty space he’s created. It gives with only a bit of resistance, and sends Sam stumbling backward due to momentum and weight.

  


The young mer falls ungracefully onto his back, rock pressing harshly onto his chest until it’s shoved off to the side. Sam goes to swipe his bangs out of his face but only manages to get sand in his eyes. “Eh!”

  


“Oh,  _man_! You do not realize how much you appreciate open space until you’re confined to a three-by-eight death cave, let me tell you.” The other mer grunts, presumably stretching as Sam hears a few pops and moans.

  


Sam rubs the heel of his palm into his right eye, sitting up. “How did you get trapping in there anyway?” he asks, blinking a few times before setting his gaze on the mer he’s saved. He’s very tan, and his tail is—

  


His tail—

  


His tail is  _grey_.

  


Every one of Sam’s bones seem to turn to ice, and the world stops turning. He’s so shocked he can’t move, can’t do much of anything but stare wide-eyed at the  _shark_.

  


The shark he just  _rescued_.

  


“Is there something on my face?” 

  


With those words Sam’s broken from his trance and swimming as fast as he can. He’s swimming so fast his bag is pressed snugly to his side, not waving in any way. He’s swimming so fast his tail feels as if it’s about to snap in half any moment. He’s swimming so fast it takes minutes to realize he’s not swimming up. He’s swimming so fast that when Sam finally gathers the courage to look behind him, he realizes he’s completely lost.

  


Heart beating erratically, Sam tries to spot something familiar to no avail. He tries to remember which direction he came from but cannot recall, too much adrenaline pushing him to just worry about it later and find somewhere safe to hide.

  


Deeper into what must be some sort of trench is another small cliff, this one generously surrounded by plants. Sam swims quickly towards it and hopes no other predators are around. 

  


As luck would have it, there doesn’t seem to be any sign of life, and there’s a very small opening in the slope, much like the caves he found before. 

  


Sam only takes one look inside before cramming his tail inside, holding back tears. When he’s completely hidden in the small opening he starts to softly cry.  _Great_ , Sam thinks in dismay,  _now I’m fucking lost and I’m going to get eaten out here_.

  


Sharp edges aline the sides of Sam’s hiding spot, some of which scrap his tail and skin painfully as he sobs. Sam covers his mouth to be quieter and tries to calm himself. He’s unsuccessful, as the impending feeling of being found weighs more heavily than any rock ever could.

  


It takes a very long time for Sam’s adrenaline rush to crash, and even longer for him to stop crying. What’s he going to do? His heat is going to happen in a few hours and he has no clue where he is! Not to mention he’s deep within predator territory. The chances of him managing to find his way home  _and_  not run into another predator are astronomically slim.

  


Sam cries and cries. A horrible wave of nausea hits and he rests his head very carefully. He feels icky and so tired. His bag presses uncomfortably against his stomach. 

  


He’s so scared he doesn’t even consider leaving the small cave. The young mer instead curls up and closes his eyes, unintentionally falling into a fitful slumber.


	2. Chapter Two

**Notes for the Chapter:**

> hope you enjoy ;)

Sam jolts awake and hits his head unforgivingly against something sharp and solid. He’s confused for only a moment because the pain jogs his memory. Sam stills in his hiding spot, once again more scared than he’s ever been in his whole life.  _How long have I been asleep?_ Sam thinks.  _How will I ever get back home?_

 

Although he doesn’t have a clear view of the outside world, Sam can tell it’s now darker. He’d still be able to see if he hypothetically ventured back home, but it would be even harder than it was a few hours ago. Any remaining hope Sam might have had diminishes. He’s always been somewhat of an optimistic mer, but this situation cultivates no positivity. Sam was dead the second he swam away from that shell-littered cliff. 

 

It takes a few minutes, but eventually he’s gathered enough bravery to scoot forward and check outside. Just because he’s accepted his fate doesn’t mean he shouldn’t at least  _try_  to make it back home. 

 

Sam audibly gasps when he sees the shark from before a few feet away, pacing ominously. He quickly jerks back, hurting himself on the sharp rocks.  _Oh, Poseidon, help me._

 

“Are you finally awake? I was starting to think you died of fear or something in there.”

 

Sam’s brain doesn’t recognize the bored, cranky tone of the shark’s voice. It just recognizes it’s a voice that belongs to a  _shark_. A shark that probably eats mers like Sam all the time without a second thought. He pushes himself as far back into his hiding place as possible and sobs.

 

“Oh, jeeze. Don’t cry. I’m, uh...” If Sam didn’t know better, he’d say the shark was attempting to pacify him, albeit enthusiastically. 

 

Considering he’s less than a yard away from certain death, Sam only cries harder.

 

“Stop crying! I’m not gonna hurt you, okay?” the shark says without any effort to console. 

 

It isn’t said very convincingly, but Sam wants to go home so badly and see his family again that he dares to listen. He forces himself to stop crying with a loud exhale.

 

“I’m gonna be pissed if any of that snot floats over and touches me, kid. Now can you come out already?”

 

Sam takes a few shaky breaths. “Why?” he whispers, slowly gliding forward to look out at the shark. 

 

He’s still hovering in the same general area, no closer than he was before. “How do you think I found you? You’re nearing heat, omega. And that is  _not_  something you wanna experience out here.”

 

“I wanna go home,” Sam whimpers, lip quivering uncontrollably.

 

The shark looks at him with an uncomfortable expression. “Uh, yeah I would too if I were you. But there’s no way you’re gonna make it home like this. I can take you back to my nest for the night and show you home in the morning.”

 

Such tempting promises. Sam kicks himself for being so gullible, so foolish, because there’s no way this will end up with him safe at home tomorrow morning. “Your... Nest?”

 

“Yeah, it’s not far from here.” The shark swims a little closer and Sam retreats. He hears a long sigh. “Seriously, I’m not gonna eat you.”

 

“Why not?” Sam asks disbelievingly.

 

“You’re just a kid. I’m not gonna eat a kid.”

 

Sam swallows and takes a few moments to weigh his options. He could refuse and stay here until sunlight, then attempt to find his way home while either on the cusp of heat or  _in_  heat. Or he could go with the shark.

 

Staring intensely at the sand, Sam carefully maneuvers himself out of the small hole without hurting himself too badly. He whines once he’s in the open, head still down. “Please. Please don’t hurt me.  _Please_.”

 

There’s another loud sigh. “I told you that’s not something I do. C’mon, it’ll be too dark to hunt soon.”

 

Sam sniffles and forces himself to look at the shark. His tail looks very strong and powerful, along with the rest of his body. The shark’s upper half is well-utilized by the looks of his abdominal muscles and biceps. Definitely an alpha.

 

“I...” Sam wraps his arms around his stomach pitifully. “I hurt.” His face flushes with shame, unable to truly explain his discomfort.

 

The shark — his name was Dean, wasn’t it?— considers him before slowly swimming closer. Sam’s eyes stay locked with his, pleading to be treated as promised and not ripped to shreds.

 

He’s only a fin away when he stops, leaning down. “I’ll carry you, then.” Sam’s eyes widen when he sees the unbelievably sharp teeth Dean’s talking around. 

 

Without asking for permission, Dean scoops him up like a pup and holds his stiff body close to his chest. Sam whimpers, both incredibility terrified to be in the arms of a shark and in pain from cramps. 

 

“Well don’t get too comfortable,” Dean says wryly as he begins swaying his tail side to side.

 

The dry humor does nothing to relax Sam or ease the tension. As they travel to Dean’s hopefully empty nest that isn’t filled with hungry pups his age, Sam finds the courage to look at the shark.

 

His skin is very tan, as he noted originally, but up close Sam sees that he’s dusted with freckles. His eyes are the same green as kelp. His jaw is rather strong and he’s got very,  _very_  sharp teeth. 

 

They travel in silence for a long time, and Sam’s feeling more regret by the minute. He can’t stop himself from nervously blurting out, “Are you going to feed me to your mate?”

 

Dean looks at him as if he’s grown two legs. “What? No! No, I’m gonna—I’m serious, Sam. Just spend the night and I’ll take you home in the morning. No strings.”

 

Sam sighs very quietly.

 

A few more minutes pass before they reach a decently sized cave practically hidden due to the simple fact all the rock looks like one big wall in the dark. They enter the mouth of it, and Dean slowly swims a few more fins before carefully switching to hold Sam with one hand. 

 

Sam’s laid down on what feels to be a really, really old bed. Like one an elder of the colony might still have. He immediately feels around to get an idea of what is surrounding him.

 

“I’m gonna get some grub really quick, okay? Stay here.” Without any other words, Dean’s shadow swims towards the light at the mouth of the cave before disappearing altogether.

 

Less anxious and not nearly as terrified as he was before, Sam squeezes the coarse pillows he’s resting on. Who’d sleep on something like this? It’s better than a hole in the ground not much bigger than oneself, but still. Sam feels around timidly for somewhere to put his bag before gently setting it on the cave floor.

 

Dean returns when Sam’s close to falling asleep, startling him as it’s now very dark. “Sam? I got some fish.”

 

A hand suddenly feels his chest curiously. Dean’s probably just trying to pinpoint Sam’s location, but it’s still invasive and scary. “Ah!”

 

“Oh, sorry. It’s just me. Where’s — Gimme your hand.”

 

Sam’s hand is suddenly filled with the familiar weight of a fish. He smells it. How did Dean catch fish so quickly? How was he able to find fish this hearty, let alone in the dark? As he begins to nibble on the fish he silently reflects on how good of a hunter Dean must be. Maybe he really wasn’t going to hurt Sam. After all, no matter how fast of a swimmer he is, Dean probably would still be able to catch him.

 

A disgusting, gluttonous sound tears through the water as Dean presumably devours his own fish. Sam scrunches up his nose but doesn’t comment because that fish could’ve just as likely been him.

 

Sam hands off the remnants of his meal when he’s full, and Dean takes it before making a few noises that would imply he ate Sam’s scraps. 

 

“Scoot over. You’re lucky I ain’t making you sleep on the floor.”

 

There must be some kind of platform behind him, because Sam’s back brushes against a wood-like structure. Dean takes all of his sensory attention, though, when he joins the bed. His body is much bigger than Sam’s and even if Sam wasn’t here it seems like Dean still wouldn’t fit comfortably.

 

“T-Thank you... Dean.”

 

Dean grunts. “Yeah. Just don’t push me off in the middle of the night.”

 

-

 

Sam wakes up slowly, so warm and cozy he’s sure it was all a horrible dream and he’s back at home in bed.

 

A loud snore in his ear makes him reconsider.

 

It’s bright inside the cave and brighter still outside. Sam calms himself and goes over last night’s events, realizing only after he tries to sit up that Dean’s... Holding him? 

 

Dean’s arm is draped over his stomach and they’re chest-to-back, a position usually reserved for mates. Sam blushes and squirms because this is  _so awkward_.

 

His squirming effectively wakes up Dean, the shark pulling away in confusion before remembering. “Oh. Morning.”

 

Sam feels very, very hot. “Morning,” he whines, hungry and uncomfortable. 

 

The young mer is too distracted with himself to hear Dean’s quick sniff. But Sam does notice when Dean gets off the bed. “Guess I better go get breakfast. You’re gonna need a lot of energy for, uh, yeah...”

 

Now that it’s illuminated by the outside world, Sam takes a moment to look around in Dean’s nest. As he suspected, there’s a decorative piece of wood sandwiched between the bed and the cave wall. It doesn’t really match anything else, but perhaps there’s sentimental value to it. There’s a few shelves carved into the wall right of the entrance. On them rest strange objects Sam’s never seen, along with a few beautiful sea shells. There’s also a bunch of crates stacked in the corner of the cave opposite of the bed. Sam’s surprised to see that  _this_  is what a shark nest looks like. It just seems so ordinary and not... Shark-y?

 

Sam’s so preoccupied with his observations he misses Dean exiting the cave, and he’s shocked to notice his disappearance when he eventually does. 

 

Playing with the loose threads on one of Dean’s more scratchier pillowcases, Sam tenses up when he feels the distinct sensation of slick dripping out of his slit. He whimpers, feeling to see if what he’s laying on has an extra sheet he can cover himself with. This does turn out to be the case, meaning Sam rudely slept on top of Deans blanket all night long. And now he’s about to get slick all over it. 

 

“Sam...” Dean sounds how any alpha would sound when entering a heat-heavy cave. “Uh... Has your heat started?” 

 

Sam can only answer with a whine. At this point in time he’s more worried about the fact Dean is an alpha rather than the fact he’s a shark. “ _Hurts_.”

 

The bed dips gradually as Dean settles himself on it. Sam blinks up at him, face flushed red. “Brought you some food, kiddo.” Dean presents two fish and a large fistful of kelp. “Could you... Eat this?”

 

Propping himself up a bit, Sam happily takes one of the fish and bites into it. He’s grateful that Dean’s already killed them because he’s usually unable to do that part. 

 

“Thank you, Dean.”

 

With a nod, the shark looks away, towards the entrance. “We’ll have to wait until your heat passes before I can take you home. How long will it last?”

 

Sam swallows a piece of fish, taking some of the kelp out of Dean’s hand. “Um, three days,” he answers reluctantly, not wanting for Dean to see him as more trouble than he’s worth for overstaying his welcome. “I’m s’rry.”

 

Dean looks at him again and offers a shrug. “Don’t apologize. I never have guests here, anyway.” One side of his lips turn up, but he doesn’t smile.

 

Heats aren’t really something to be ignored. They’re very persistent and no amount of mental strength would allow an omega to push it to the back of their minds. But talking to Dean is a distraction from the wetness and emptiness. Sam chews the kelp the shark has brought him slowly, looking around thoughtfully as to find something akin to a conversation piece.

 

But looking around the bare-bones nest only makes Sam think of other questions. “Don’t you have a mate?”

 

Dean blinks at the young mer with an unreadable expression. “No... I’m... it’s just me.”

 

“Aren’t there other sharks around?” Sam’s hoping against hope that the answer is ‘no’, but at the same time he feels bad that Dean lives here alone. Why hasn’t he courted a mate yet? The shark is a good couple springs older than Sam, so there’s no reason why he should still be alone. Unless maybe sharks have a different culture in that regard?

 

“Uh, yeah I’ve seen a few in this area before.”

 

Sam’s disturbed by that answer, and grips the blanket he’s wrapped himself in more tightly. He shivers when some more slick gushes out of his slit. “W-Why haven’t you mated y-yet, Dean?”

 

The shark gestures for him to continue eating. Sam complies. “Sharks don’t really... Do that kind of stuff.” Dean sounds as confused as Sam, voice wavering and vague.

 

“What do you mean?” Sam inquires with a puzzled look, brow furrowed. How could sharks not mate? How were pups created?

 

“I mean, yeah, we literally mate, but—” Dean shrugs with a frown. “We’re not all lovey-dovey like mers seem to be. It’s more of a business exchange, really.” As Sam’s face grows even more confused, Dean elaborates. “Usually when I run into a female shark we either end up fighting each other or fucking. I’ve most likely got a few pups out there, but I’ve travelled so far I probably won’t ever come across any of them. We don’t settle down in little colonies like you do. We roam freely, in places like this where nobody else wants to live.”

 

This information is completely new to Sam, who had always imagined shark society to work much like mercolonies. He’s still confused, though. Perhaps Dean’s simply expressing his preference for female sharks, but Sam’s beginning to suspect something’s fishy when he realizes Dean’s not regarding him as a horny alpha. He seems relatively relaxed, virtually unaffected by Sam’s heat. Sam leans forward a bit and notices that Dean isn’t expelling any alpha nodes. “You’re not an alpha?”

 

Dean smiles minutely. “Kid, if I was an alpha I’d be your life partner by now.”

 

“I...” Sam picks at his fish. “I always assumed you were like us.”

 

“Nah, we’re built to be loners. If we lived as mers do we’d have too much of a power struggle. Not to mention the food arrangement we’d need to figure out. I don’t think something like what would ever work.” 

 

Recognizing this as an opportunity to ask a predator every question he’s ever had for them, Sam abruptly sits up straight and grins. He’s got a shark in front of him! A real life  _shark_! It’d be a shame to waste an opportunity like this!

 

“...Do you really eat your nestmates?”

 

-

 

Sam’s three day stay got progressively more delightful every moment. Dean wasn’t certain about a few of the answers he gave the young mer, but was very insightful nonetheless. With the tension gone, Sam was able to appreciate Dean’s sense of humor and company. By the time his heat had passed and it was time to go back home, they had talked about everything from warming waters to the texture of tuna.

 

“Make sure you don’t forget your bag,” Dean reminds, waiting for Sam at the entrance of his cave. He’s not smiling, something that had become a regular occurrence after Sam’s wariness melted away and his curious nature peaked. 

 

Sam bites his bottom lip and looks around in the shark nest one last time before exiting with Dean. He’s... Sad. Which is weird to think, because just a few days ago Sam was near hysteric at the idea of a shark less than a hundred miles away from him at all times. But Dean’s proven to be a pretty awesome... Friend. It’s even weirder to consider a shark his  _friend_.

 

The shark is about to say something—probably to follow him and they’ll be back in Crag in no time—when Sam works up the courage to grab his wrist.

 

“Sam?” Dean asks with a frown.

 

Sam hides beneath his bangs, his free hand carefully feeling around in his sack. It closes gently around a tightly woven cord of sea grass. He presents the necklace with his free hand. “I... I-I want to thank you for helping me so much. For p-protecting me. And since we probably won’t see each other again, I... Want you to have this, Dean.”

 

Astonishment clear on the shark’s face, Dean slowly takes the necklace from the young mer. He rotates it carefully with his thumb as he examines it, mouth open. Sam’s beginning to worry that Dean doesn’t like it when the silence is broken. “Thank you, Sam. This is really well-made... Can I have my wrist back?”

 

Blushing, Sam lets go of Dean’s wrist. The shark chuckles at him before gently putting on the necklace. It’s the perfect length, and the green cord accentuates his eyes.

 

“It’s perfect. Did you make this?”

 

Sam nods. It was originally for Jess, but Dean doesn’t need to know that. It looks better on him than it would’ve on her, anyway. “I’m glad you like it.”

 

Dean pats Sam on his arm and looks like he has more to say, or rather wants to say more, but he instead pulls away with a cough and grunts, “Let’s get moving, Sammy.”

 

-

 

When they reach the top of the rocky slope a few miles from his colony, Sam starts to imagine how frantic the colony is with his disappearance, let alone Bobby or Karen. He has no idea what he’s going to tell them, because they’d never believe the truth. If it were someone other than him, Sam sure as Hell wouldn’t believe that mer.

 

“Stay in Crag, kid,” Dean commands with a stern finger waving in the air. “And don’t you dare ever come back here. These are dangerous parts.”

 

Sam smiles at the shark. “You’re right. I’d hate to run into a shark or something like that.” He turns towards the path he knows will lead him back to Crag, heart heavy. “Take care, Dean.”

 

“Adios, kid,” Dean bids quietly.

 

He’s just masochistic enough to look back once, and catches sight of Dean still hovering in the same spot up until he’s too far away and the water becomes opaque.

 

_Seriously_ , what is he gonna tell Bobby?

**Notes for the Chapter:**

> comments make me smile!


	3. Chapter Three

**Notes for the Chapter:**

> death and graphic descriptions in this chapter! read at your own risk!!!

TEN SPRINGS LATER

 

“Brady, that’s not funny! I know someone who’s mated to an octopus!” Jess tuts disapprovingly at the beta mer, shaking her head.

 

Whatever doubts Sam had about accompanying his friends on this soul-searching camping trip evaporate as Brady continues to provoke Jess, ultimately leading to an amusing scuffle that Jess easily wins.

 

Sam continues to draw various sketches in the sand as he laughs. “Don’t knock over the tents, guys.”

 

The blond alpha snorts, both hands holding Brady into the sand. “I think in order for that to be a possibility we’d have to fight for maybe, hm, more than ten seconds?” Jessica releases the beta before smugly returning to her spot she was sitting at previously.

 

“I think mine just needs a light current before it’s game over,” Zach laments, looking over at his tent with pessimism.

 

Rebecca laughs at her brother’s dismay. “If you weren’t preening so much you could’ve assembled it properly.” Zach blushes and Rebecca smirks knowingly. 

 

The bickering and teasing carries on for the rest of the night, up until they’ve all retired to their respected sleeping quarters. Sam’s lucky to have his own private tent, but it’s still too small for him. No one—including himself—can believe that little Sam Singer grew up to be such a tall, broad omega. He’s still certainly pretty enough, but other than that he doesn’t really look the part. But dysphoria aside, Sam’s current problem is his tail sticking out from the front of his tent. It’s irritating, but he’s still able to fall asleep.

 

Sam’s yanked out of a lovely dream at the crack of dawn by a long, shrill scream. He shoots up immediately, adrenaline filling his veins.

 

“AHHHH!”

 

There’s more bloodcurdling screams that follow the first, along with noises of a fight. And... Wet ripping noises. Along with the tangy smell of iron drifting into Sam’s tent. It’s more than obvious what’s going on outside. They’re being attacked by sharks. 

 

Sam’s much too afraid to leave his tent and swim presumably away from their attackers. He remains frozen and terrified, tears infiltrating the surrounding seawater. His friends are screaming so loudly, undoubtably being ripped apart and devoured. And Sam’s a sitting duck, practically begging to be eaten.

 

It feels as if the massacre lasts for hours, but it couldn’t have been more than thirty minutes. Sam’s still quivering in his tent, hoping that the shark(s?) have gotten their fill and swam back home with full bellies. No matter how horribly selfish it sounds, Sam’s no hero, and there’s not much he could do to a shark, anyway.

 

“Did the blond one get away?” Sam hears out of nowhere, the voice male but too muffled to be distinguished any further. 

 

“Yeah,” a female voice grunts. 

 

Sam’s very happy that Jess evidently escaped the attack, especially since he’s sure he won’t be so lucky. He strains to listen for more conversation.

 

There’s a very loud belch that makes Sam indescribably sick to his stomach. 

 

“Jo, here. Take this one with you. For you and Ellen.”

 

The sound of something heavy being dragged past Sam’s tent renews his terror. His  _friends_. How could this have happened? They  _can’t_  be dead.  _He_  can’t die. Sam muffles his sobs. 

 

It’s quiet for too long. Sam’s not sure if both of the sharks left, or if only one did—the one who dragged one of his dead friends away to be feasted on like a common fish. 

 

Unable to hold it back, Sam releases a loud, snotty sob. It rings throughout the coppery water like a gunshot. He freezes afterwards, waiting to see if he’s just signed his life away or if the sharks have taken off and he’s safe from—

 

“Don’t think I’ve forgotten about you.”

 

Sam’s blood runs cold. He’s escaped impending death before by some dumb luck, but that’s not going to happen here. This is the end, and he’s going to die gruesomely. But if the shark is already aware of his existence, there’s no harm in pleading for his life. “Please don’t kill me.  _Please_.”

 

The voice laughs cruelly. “Well, now that you mention it I really  _don’t_  enjoy hauling food back to my nest. Suppose it would be easier if it just came back with me.”

 

“Have mercy. Please have  _mercy_ ,” Sam whimpers.

 

“Now why would I do that when I could have dessert instead?” the voice purrs mockingly, now clear as it’s just outside the tent.

 

Sam almost pisses himself when his tent is suddenly yanked out of the ground, screaming in shock and horror. He’s scrambling backward instinctively, and it takes a full two seconds to realize the shark has accidentally swam into the tent. Sam takes off immediately after and hopes his head start will save him.

 

They’re on a completely flat plane of sand, however, so there’s nowhere to swim. Nowhere to hide. Sam frantically searches for his saving grace, absolutely hysterical. “Please stop. Pleaseplease _please_!”

 

“Swimming off like that just makes me want you more, mer,” the shark hisses from somewhere near behind him.

 

Sam risks making a sharp turn around, heading back to their camp. There’s rocks. He saw rocks last night, he knows he did. That’s his only hope. Getting a rock and—

 

The mangled body of one of Sam’s friends, seemingly Elizabeth by the blue-colored scales that are leftover, jars the mer briefly but not long enough for him to miss his opportunity to obtain a weapon. Sam dives into the sand carelessly, eyes locked on a particularly hefty-looking rock.

 

Sam grabs it and turns to look at where he imagined the shark to be close behind. Without much thought or technique, he throws the rock.

 

It hits the shark in the abdomen so hard that he slumps over, clutching his stomach with a groan as he stops in his tracks. “Son of a...  _Bitch_!”

 

The sun is now just reaching the sandy floor, and it reflects on a small shell resting on the shark’s chest... Held together by... Braided sea grass. Sam’s so shocked he doesn’t even remember that this is his advantage, that it’s time to swim away like he’s never swam before. The shark growls, looking up at him menacingly. Sam’s only ever seen those eyes gleam with laughter or snark, he’s never seen them so dilated with bloodlust that no green remains to be accentuated by his necklace. 

 

The shark advances, looming over Sam. “Did you just seriously throw a friggin  _rock_  at me? I’m going to—“

 

“ _Dean_?”

 

This causes the shark to halt, expression flickering between confused and enraged. “...What? Don’t think any of this small talk will—“

 

Sam’s eyes burn so horribly from crying. He looks at the shark with such lost eyes. “Dean!” He can’t say much more, not even to save himself, because this has to be  _Dean_. And that makes him more upset than it probably should.

 

Dean growls again and pounces on Sam’s prone form, holding the mer’s wrists to the sandy ground. His teeth are pink and chunks of flesh are still stuck between them. “What kind of game are you playing at!” he roars in Sam’s face.

 

“Oh—Oh—Oh, fuck!  _Dean_!” Sam wails underneath the shark. Not only is he about to be eaten by a shark, but a shark that never left his thoughts no matter how long it’s been since they last saw each other. A shark that he foolishly considered a remarkable friend. 

 

Damn Sam’s growth spurt, because there’s no recollection on Dean’s part, and he suddenly strikes. Wickedly sharp teeth embed into Sam’s left shoulder and he screams so loudly his voice breaks halfway through. Dean’s necklace presses sharply into Sam’s skin.

 

The pain that Sam experiences is like no other. And it will only worsen as Dean begins to take bites, as he inevitably shakes Sam back and forth with nothing other than his mouth—

 

Sam’s sure it’s starting as Dean abruptly pulls back, shredding skin and tearing muscles. Sam wails miserably as he waits for a new site of pain to emerge, eyes tightly shut as he continues to scream.

 

But there’s no new pain. Only the pressure of Dean’s hold and the feeling of his mutilated shoulder. A long time passes, a really long time, without anything but Sam’s cries. Eventually, though, he’s able to open his eyes and tries to understand what’s happening. 

 

Dean’s pupils are no longer dilated. They’re green and unsure and dumbfounded. Sam stops screaming out his pain in favor of grunting loudly with his mouth closed. Maybe this isn’t the end. 

 

“S... S... Sam?” 

 

The shark’s bloody mouth swirls with Dean’s mossy green eyes before the distorted image completely fades to black.

 

- 

 

As an omega, Sam’s regrettably accustomed to waking up in the middle of the night due to menstruation or heat-related discomfort—even the occasional muscle spasm. Needless to say, Sam’s not a stranger to waking up in pain.

 

Even still, it’s not delightful by any stretch of the imagination to wake up from a throbbing ache in ones shoulder, no matter their experience.

 

Sam mewls, still caught between a dreamless slumber and consciousness. He moves thoughtlessly and his whole body screams in protest. Too disturbed to fall back asleep, Sam reluctantly opens his eyes with a frown.

 

The sight of a uneven cave ceiling is confusing. Didn’t Becky insist on bringing tents? After all, Sunspot Plain is completely flat. One cave would be seldom found, let alone enough for all five of them. Sam sits up a bit, groaning when another pain rips through his shoulder. He’s drawn to inspect it, as anyone would be, and looks.

 

His neck isn’t happy with the angle, but Sam’s able to locate the source of his pain. His shoulder is wrapped halfheartedly with blood-soaked fabric, the skin surrounding the wrap red and tender. Sam shivers.

 

_We were attacked_ , Sam thinks searchingly.  _Attacked by sharks. Dean was there. Dean chased me, bit me._  Though, Sam’s still disoriented and looks around for clues.  _How did I escape? Who wrapped the bite?_

 

The cave Sam finds himself in is hands down the most minimalist cave he’s ever been inside of. He’s resting on top of various fabrics piled in an attempt of a bed. There’s not nearly enough to be comfortable. 

 

Next to the bed is a small crate that Sam has no interest to look inside. And... That’s it. The rest of the cave is bare and untouched. It’s not a wide cave, but it’s rather long. Sam would say the entrance to the cave is about nine fins from the bed. 

 

Sam attempts to sit up further. He only succeeds in upsetting his wound, turning just in time to watch a bit of his blood leak out into the surrounding water.

 

“D-Don’t get up.”

 

Sam’s head whips to the mouth of the cave, towards the familiar voice. The distance casts the owner of said voice as a shadow, but Sam already knows it’s Dean. It’s reluctant and gruff, but certainly Dean. The young mer bites his bottom lip and curls into himself as much as possible without hurting his shoulder.

 

Dean hovers by the entrance, teetering back and forth between the threshold. “It’s... Better if you stay laying down.” 

 

Why is he here? Why isn’t he dead? Sam’s so bewildered he feels tears sting his eyes. “What am I doing here?” he croaks, self-preservation be damned.

 

A beat passes without providing an answer. Sam rubs his eyes and whines. As he’s blinded, a gentle swish of water reaches his ears, and Sam freezes with the knowledge that Dean’s now closer to him.

 

“S-Sam...”

 

Sam works up the courage to look at the shark. Dean’s now only two feet away, hovering lazily. His body is nearly as Sam remembers, albeit older, but he’s also got silvery scars and spiky stubble on his jawline. A bolt of fear strikes Sam when his eyes fall on Dean’s pursed lips, remembering the sharp teeth encased behind them.

 

“Please, don’t keep me here,” Sam whispers hopelessly. “If you’re going to... Eat me, just do it now.”

 

Dean breathes in sharply. “No. No, Sam. I didn’t... I’m so sorry.”

 

Arms curled protectively around himself, Sam looks past Dean and thinks of his dead friends. He can’t believe they’re really gone, still in denial about the whole situation. “Is it really you, Dean?” Sam asks hesitantly. 

 

“Yeah, I’m... I’m Dean,” the shark says in response, startling Sam when he moves to lay on the cave floor. “Sorry.”

 

With Dean now positioned underneath his eye level, Sam lets himself be comforted by a false sense of dominance. “What am I doing here?” he repeats with artificial bravo.

 

“You need rest,” Dean answers simply, gesturing to Sam’s shoulder with his own as non-threatening as possible. He almost sounds robotic, as if he hasn’t had a conversation with another person in ages. “I wrapped your shoulder.”

 

Sam doesn’t think Dean meant it condescendingly, but the statement still irks him. The anger boiling inside him grows along with his nerve. “You bit my shoulder,” Sam sneers.

 

While the shark certainly doesn’t have a way with words, his expression speaks volumes. Dean’s guilty face only makes Sam more upset. “I’m so sorry,” he whispers.

 

“You killed my friends,” Sam accuses, clenching his fists.

 

Silent, Dean looks down and nods softly.

 

Sam finds Dean’s posture to be audacious and growls, “What the hell  _is_  this? Am I supposed to just stay here while you play hospital?”

 

For all his cockiness and predatory moves when he attacked Sam, Dean doesn’t seem to be able to do anything more than meekly look up at the young mer’s wound, slumped on the cave floor. “You can’t leave like this... You could bleed out.”

 

“So? What do you care?” Sam demands, holding back tears of frustration. Maybe Sam should cut Dean a bit of slack for not knowing how to carry a conversation with someone he’s attempted to literally consume, but all he can think about is how his friends are dead, nothing but nameless bones and digested flesh. If they were discarded so easily, why is he still here? 

 

Dean finally meets Sam’s stormy brown eyes. “I... I wouldn’t have...” he trails off, coughing. “I-I didn’t know it was you.”

 

“Why should it matter if it’s me?” Sam asks challengingly. After all, it’s been years since they’ll last seen or spoken to each other. Dean was just a happy memory Sam recalls every so often. He can only assume Dean thought of him the same way, and now that he’s not a kid anymore Sam should be considered fair game as far as hunting goes. 

 

“You’re...” Dean frowns, almost as if he’s forgetting how to speak in real time. “You’re Sam,” he replies dumbly.

 

Fighting back tears—he’s already cried so much and it’s taking a lot out of him—Sam whispers in turmoil, “I’m a mer.”

 

Without hesitation, Dean corrects, “You’re my friend.” He says it like they’ve known each other their whole lives.

 

“I haven’t seen you in many seasons, Dean.” Sam sniffles, frowning at the shark. It’s insanity, but he feels like he’s talking to a small pup, trying to explain why he should be killing him.

 

Dean’s hand trails up to his necklace with purpose, not looking away from Sam’s eyes. “I’ve... Thought of you often. And since I couldn’t just stroll into Crag without risking mass panic, I kept... Moving. But I try to come back right before spring, hoping to... Catch you.” Dean flinches at his own choice of words.

 

Sam wipes his sullen eyes, thinking. “You... Come back before spring? To find  _me_?”

 

The shark laughs briefly, but without humor. “I know it sounds weird, but yeah. I always hoped I’d run into you again. You gotta understand that when I imagined it, it wasn’t anything like this.”

 

“I would hope,” Sam agrees, anger dissipating. He winces again as his shoulder throbs unpleasantly.

 

“Could you lay down?” Dean suggests timidly. “Your body’s under a lot of stress already so I think—“

 

“Yeah, yeah,” Sam grunts in agreement. He complies, slowly laying his body back down horizontally. Both men look to Sam’s tail fin, which is hanging halfway off the ‘bed’.

 

Dean coughs awkwardly. “Sorry I don’t have anything better for you to sleep on, I’ve only been back for a few days.”

 

Sam tries very hard not to think about where the rags could have came from. He refuses to think about how Dean probably took them from his food—stripping, stealing, and the like. “...How far are we from Crag?”

 

“Less far than where I found you,” Dean answers ambiguously.

 

To help cope with the pain, Sam buries his hands into the fabric underneath him and tightly grasps it. “This feels strangely familiar. Me, unable to swim myself home due to unforeseen circumstances,” he muses. “And you, hospitable in allowing me to stay in your nest until I’m better again.”

 

Dean’s lips curl upwards a hair. “I don’t entertain very often, but you do happen to be my favorite guest.”

 

Sam’s belly groans loudly. He looks at Dean sheepishly. “Could you, um—?”

 

“Yeah, don’t worry about it. I’ll be right back.” Dean slowly gets up, scooting away from Sam as he does. “Don’t wait up.”

 

Sam watches the shark leave, turning his head towards the ceiling once he’s disappeared. It’s unlikely he’ll be able to fall asleep, but Sam decides to rest his eyes while he waits for Dean to return.

 

Much later, after Dean’s filled Sam’s belly full of fish and sea grass, Sam idly picks at his bandages. They’re both sitting on Dean’s bed—which Sam has more or less claimed as his own—with the young mer leaning against another mound of fabrics as a makeshift pillow. Sam hisses when his fingernail digs in with too much zeal.

 

“Don’t,” Dean grunts scoldingly, catching Sam’s hand in the dim light and setting it in his lap. His fingers linger then let go. “I should change that before it gets too dark.”

 

Looking at the shark, Sam shrugs his good shoulder. “Doesn’t the blood bother you?” he asks curiously.

 

Dean’s face scrunches up. “It’s... distracting, but... I’m more than capable of controlling myself, Sam.” He sighs deeply, examining Sam’s filthy bandages. “This will probably hurt a bit.”

 

Ever the reasonable patient, Sam sits still while Dean fiddles with the bloody wrap, clenching his teeth. The soiled fabric is relatively stuck to his scabs, but a gentle tuck detaches it with minimal discomfort. Dean still apologies.

 

Once his wound is completely exposed, they both ogle it but with vastly different expressions. “You’ve got a hellava bite,” Sam jokes to lighten the mood. 

 

Dean’s fangs have left a sizable impression in Sam’s tender flesh. The wound is still irritated and inflamed, but not infected or unbearably painful. Even when Dean’s fingers ghost over the cuts, the sting is only minor. Although he doesn’t have any frame of reference, Sam can tell the bite is going to leave a nasty scar.

 

It’s only when Sam hears a choked sob that he looks away from his wound, brown eyes falling on Dean. He’s curled into himself a bit, face full of anguish. “I’m so sorry, Sam,” the shark whispers.

 

Sam can’t help but take Dean’s exploratory hand and carefully lace their fingers together. He feels a momentary pang of guilt, thinking of his friends. Sam sighs.

 

It isn’t uncommon for someone in Crag to venture outside mer territory, seeking adventure, treasure, or even  _shells_. People leave and are never heard from again. This might sound ominous, but there have been many mers who arrive in Crag with colorful stories of how they happened upon the colony. So it’s likely many mers just decide never to come back, but there’s also the chance they met an untimely demise. And whether it had been by starvation or predator... No one will ever know.

 

Sunspot Plain hasn’t ever been known as a safe place—anywhere out in the open is dangerous—but Sam’s never heard of it being close to shark territory. 

 

But that’s not important.

 

The point is: stuff like this happens occasionally. Camping was a risk they were all willing to take and the majority of them paid the price for it. Sam feels guilty for disregarding his friends’ deaths so quickly, but ‘tis the way of the sea. He’ll never forget the happy memories they all shared, but holding a grudge against Dean for their deaths seems... Unfair. Poseidon made sharks exactly as they’re meant to be, so who is Sam to say Dean shouldn’t hunt mers? To say Dean was wrong for following his  _instincts_?

 

Maybe Sam is a bad friend. He certainly feels like a bad friend. But remaining upset is pointless. There’s nothing he can do to change the past. 

 

Squeezing his friend’s cold hand, Sam smiles. With complete sincerity, the young mer replies, “I forgive you.”

**Notes for the Chapter:**

> I hope this wasn't too unbelieveable or OOC... Did you enjoy it? Please comment to increase my self-worth ;)


	4. Chapter Four

**Notes for the Chapter:**

> Sorry for late upload and any grammar mistakes

“You’ve never had lobster before?”

 

Sam watches the red creature twist unhappily from underneath Dean’s hands, shaking his head. “No, it’s too expensive in Crag. The supply and demand ratio is astronomically skewed.”

 

The shark squints at the lobster, mumbling ‘astronomically’ to himself. It’s clear Dean isn’t familiar with the word, and Sam giggles. “Very much,” the young mer explains without prompting, much to Dean’s internal relief. “It’s very much skewed.” For as many horror stories Sam has heard of mers spotting a shark’s fin piercing the surface of the water in the distance, they must not go up at night to admire the stars. That’s something Sam will have to introduce Dean to. Having a shark as a companion comes with many benefits, Sam’s realizing. He can pretty much go anywhere now without fear of being attacked. If anything were to bother Sam, there Dean is, ready to defend the young mer.

 

“Crag is practically next to a breeding ground for these friggin things, though.” Dean glances at a nearby patch of sea grass and thinks for only a moment before plucking some blades. He begins to wrap the lobsters claws as to prevent it from snapping at them in defense. “Do you not know about it?”

 

Sam shakes his head again. “The vendors probably do. But all we really have is tuna. I think we’re just happy to stick with whatever’s worked since the beginning. It’s too dangerous to search further out for food. Only the daring marketers try, and their prices reflect their strive.”

 

Peacocking over the prospect of introducing something not only new to Sam but allegedly pricey, Dean presents the lobster. The young mer takes it carefully, frowning at the sabotaged pinchers. “What did you do to it’s hands?”

 

Dean’s proud smile falters slightly. “Oh, I just wrapped them. So it can’t snip you.” He knows that while they aren’t very fast creatures, their claws can sever a finger.

 

Holding the sad, defenseless lobster makes Sam feel powerful. He doesn’t like this power, though. He realizes this is the same dilemma he faces when it’s time to eat a live fish. Is this what Dean feels like when he comes across an unsuspecting mer? What he feels when they’re bleeding to death under him, nothing but ribbons of their former self?

 

“It’s cute,” Sam laments, unwrapping the lobster’s claws. “I can’t... I can’t kill it.”

 

Dean quickly takes the lobster once it’s only means of defense is returned. He clearly doesn’t want it to hurt Sam, even minimally. “What?”

 

Blushing, the young mer looks down at the sand they’re laying on. Sam plucks a dark piece of gravel from the ground and rolls it around with his fingers. “I’m not trying to be unappreciative or anything, I just don’t like when they look at me.”

 

“Look at you?” Dean repeats slowly.

 

A brown lock of hair escapes from behind Sam’s ear and tickles his nose. He nods with an embarrassed visage, looking back to the writhing lobster encased under Dean’s hands. He has to look away because the sight is so pitiful. “Sorry.”

 

Dean, for the first time in awhile, seems lost for words. “Uh.” He twirls around so that he’s facing away from Sam. “May I?”

 

Sam can’t help but giggle at his tone, looking up again. He understands Dean’s intentions and gives his affirmative. Hidden from Sam’s view, the condemned lobster meets his end with a sickening crunch. Sam flinches a bit and tries to spare his appetite.

 

When the shark turns back around the lobster is in several pieces. Dean offers a large (in comparison to the others) chunk of meat to Sam that he clearly tried to carve out as carefully as possible with his claws. “Thank you.” Sam curiously takes the white meat, smelling it. Once he’s satisfied with his investigation he takes a bite.

 

Dean blinks at him expectantly. Sam smiles at him. He swallows and says, “I like it.”

 

“I’m glad. I’ll bring you lobster anytime you’d like, Sammy.”

 

Ignoring the nickname, Sam shrugs. “I’m not much of a picky eater, but if you’re offering...” His eyes beam with mischief. “I’ll take full advantage of that promise.”

 

“Hey, cut me a little slack. I can’t exactly do door delivery, y’know,” Dean quips, voice becoming progressively more somber. 

 

Sam realizes it’s time to talk about the whale in the room. He takes another bite, thinking over what he’d like to say. “Eager for me to leave?” he asks playfully, putting the ball in Dean’s court. 

 

Dean, surprisingly, leaves no room for fooling around. He shakes his head adamantly. “No, I’m... I’m really not. But you’re not on your death bed, so... Shouldn’t we be heading back?” 

 

It’s been nearly two weeks since the incident at Sunspot Plain. Sam feels completely fine, his shoulder feels completely fine. By all means he should already be back at Crag, reuniting with his family before hopefully finding Jessica and checking on her. But that same feeling Sam had when he left Dean the first time is heavy on his chest. Sam had returned originally because he was so young, future ahead of him and no where to go besides Crag. Not to mention his family. But now... Now is different. With Bobby passed and no mate waiting for him in Crag, he finds himself attracted to the idea of staying with Dean. But Sam isn’t impulsive and he knows he’ll have to think about it longer. 

 

“If it’s all the same to you, I’d like to stay a little longer.” Sam licks his fingers, finishing his piece of lobster. “We’re having fun, right?”

 

Even if Sam didn’t want to stay, the way Dean’s eyes light up and his grin would’ve been worth the hassle. “Buckets.” He offers Sam more lobster meat, taking the smaller pieces for himself. 

 

Sam accepts graciously. Watching Dean pick at the lobster corpse, he reflects on how if he were to propose to Dean they remain together permanently, he should be able to name a number of things about the shark. They’re well-acquainted with subjects like food and biology, but it seems like both of them have been too shy to ask more personal questions. Sam feels like he’d be able to answer anything at the moment, so he confidently breaches the subject. “How was your childhood?”

 

Dean tenses up a bit, eyes locked on the lobster. Sam’s about to say ‘never mind’ and apologize when the shark clears his throat and answers. “My childhood was a little weird, by shark standards, anyway. Normally pups follow around their mom for a couple springs before we go off on our own, but... My dad pretty much took on that role. He wasn’t a very good substitute, you can imagine, but he tried his best.”

 

Nodding along, Sam asks, “Did something happen to your mom?”

 

“She died when I was a pup,” Dean answers quietly. Sam wonders if he’s the first person Dean’s ever shared this information with. “The way my dad tells it, somebody attacked her in our nest while he was teaching me how to hunt.”

 

Sam reaches out to comfort Dean. “I’m sorry that happened, Dean,” he says sympathetically. “I bet she put up a good fight. I can’t imagine anything being strong enough to take down a shark.” He removes his hand after stroking Dean’s arm briefly. Sam fleetingly wonders why they had a nest when Dean told him that sharks don’t really do that kind of ‘lovely dovey’ stuff. But he doesn’t ask, recognizing it as a sore subject.

 

Dean nods, lifting his head. “It was a long time ago,” he dismisses. “After that my dad raised me. I left around my tenth spring. I’ve been on my own since.”

 

The idea of being completely independent at the tender age of ten disturbs Sam. Even if it is instinctual, it’s hard for Sam to wrap his head around. So he replies honestly, admitting, “That’s insane to me. I wouldn’t last a moment out here by myself right now, let alone at ten.”

 

The tension plummets as Dean gives a cocky smirk. “You’re not kidding, seeing as I found you in a open field.”

 

Sam squints with mirth. “It’s a different change of pace. And not usually bombarded by sharks.”

 

Rolling his eyes, Dean shovels the last of the lobster down his throat gracelessly. Sam makes a face at him for being so gross. “How about you, then?” he asks with a full mouth.

 

“Swallow first, please,” Sam reprimands, trying not to smile but failing. “Mine’s weird, too. I actually don’t know my birth parents. But I’ve come to think of my adoptive parents as my birth parents. My dad, Bobby, passed away recently. He’s the one who found me.”

 

Brow furrowing, Dean inquires, “Found you?”

 

“I was left technically outside of Crag. Bobby heard crying past the border and came and got me,” Sam explains with a shrug. He knows it’s a strange story but he’s had his whole life to come to terms with it. He can only thank his birth parents for leaving him by a colony rather than abandoning him in the middle of the sea.

 

Dean frowns. “Wow, I think you actually got me beat. That is weird.”

 

The young mer shrugs in response. “Meh, I’d pick someone willing to raise a pup that isn’t their own than someone willing to give up their own flesh and blood any day.”

 

“I’m sure it was for good reason, Sam.” Dean tries to hide a yawn and fails epically.

 

Feigning offense, Sam huffs, “Is my sob story seriously boring you?”

 

Dean yawns again and points an accusatory finger at Sam. “This is your fault for all those naps we’ve been taking.”

 

“‘We’ve been taking’? I don’t recall demanding you join me. I was on bedrest.”

 

“Yeah, which ended a week ago,” Dean points out teasingly. He sets the lobster’s remains on the ground before getting up. 

 

Rising, Sam yawns out, “Shut up, jerk.”

 

Dean laughs, gesturing for Sam to follow him back to his nest. “See? You better lose that grump after our nap. Bitch.”

 

 

 

A few days later, while they are finishing up dinner together in the dim lighting of Dean’s cave, Sam remembers his idea. He licks his fingers with a smile before proposing it. “Have you ever stargazed before, Dean?”

 

Dean frowns at him. “Uh, maybe. What is that exactly?”

 

Sam’s not entirely surprised Dean doesn’t even know what ‘stargazing’ means, so he patiently explains. “Stargazing is when you go up to the surface and watch the stars.”

 

Instead of nodding, Dean blushes. Sam wishes it was lighter outside so he could properly admire the way Dean’s freckles pop out against his flushed skin. “What’re... Stars?” he asks reluctantly.

 

Taken aback, Sam all but gasps. “You’re kidding.” But Dean seems completely serious and embarrassed for it. “You’ve been to the surface before, right?”

 

Dean scoffs. “Of course.”

 

“At night?”

 

“Occasionally, I guess.”

 

Sam twirls the fish bones in his hand thoughtfully, maintaining eye contact with the shark. “Stars are the lights in the sky.”

 

“Oh!” Dean exclaims. He rubs his face with a groan. “I’m so stupid. Yes, duh, stars. I forgot that’s what they’re called. Stars. No, I never... Gazed or anything like that.”

 

Laughing softly, Sam dismisses Dean’s apology. This isn’t the first and certainly won’t be the last time Sam’ll need to explain something that’s so obvious to him but unnecessary—and therefore purposeless—to Dean. It’s silly to imagine Dean as a pup being introduced to stargazing, anyway. “It’s okay. Would you like to go stargazing with me? Right now?”

 

“Of course.” Almost every request Sam has had over the past weeks has been met with agreeable enthusiasm. Which is to be expected because of Dean’s guilt, but Sam wonders when it’ll wear off and he’ll see the more unbiased side of Dean. He doesn’t seem unhappy with the request, but Sam doesn’t want to coerce the shark into something he’s uninterested in. “You’ll have to show me how, though.”

 

Show him how. To stargaze. Stargaze. Gazing at stars. Sam snickers into his hand as he nods briefly. “Hopefully you’ll be able to keep up,” he teases, offering a hand.

 

Dean doesn’t respond, recognizing the sarcastic tone in Sam’s voice but not having a proper retort ready to fire back. He grips Sam’s hand tightly and gently pushes his way to the front so he can lead. Sam follows without hesitance, still smiling from their conversation. 

 

The journey is slow-going because of how dark it’s become outside. Dean’s clearly cautious as they begin to ascend, keeping Sam as close as possible without their tails getting in the way. It’s a little awkward to move as one when they flap in different fashions. Although he’s been with Dean awhile now, he still finds the shark’s swimming rather remarkable and exotic.

 

They breach the surface after a few minutes, and Sam instinctively gasps so that he’ll take in oxygen through his mouth rather than gills. Sam feels a momentary burn in his lungs—he hasn’t used them in awhile—before his body adjusts. Situated, the young mer looks to Dean, who paints a funny picture because he’s still neck deep in the water. “You can join me up here anytime you like,” Sam jives.

 

Dean gives his familiar look of ‘what the hell are you talking about’, making Sam frown. “Uh... Can you breath right now?” Dean asks in confusion.

 

Sam nods and brings Dean’s hand up to his now-closed gills on the left side of his neck. “Yeah, I’m using my lungs. It’s more comfortable,” he explains slowly, lowering Dean’s hand but keeping them intertwined.

 

“Lungs,” Dean repeats, eyes growing sheepish. He has the most pitiful expression when he doesn’t understand something, which Sam finds more than endearing.

 

Sam has to stop himself from pointing out Dean must be somewhat familiar with lungs. He’s probably eaten them before, whether he realizes it or not. “You don’t have lungs, do you?” Dean seems unsure of how to answer, so Sam probes. “Can you breathe air?”

 

“No.” Dean looks pouty now. Sam’s both amused and intrigued.

 

“You only have gills?”

 

“Yeah, of course,” Dean snorts, still looking ridiculous from Sam’s perspective. “I didn’t realize there was an option B.”

 

“Huh.” Sam shrugs. “Well, mermaids have lungs. We take in air so we can stay above the water.”

 

Equally intrigued, Dean asks, “How long can you stay above water?”

 

“Oh, I could stay like this for however long I wanted. But we can’t leave the water for too long before our scales dry up and become dehydrated.” Sam hums. “I guess this isn’t too surprising. I can’t see what evolutional benefit this would have on sharks.”

 

Dean grunts. “What kinda evolutional benefit does it have on mers, then?”

 

Sam thinks for a moment. “I’ve heard of colonies that aren’t strictly underwater. I would think that sometime we were forced to adapt to an unfamiliar environment and the trait stuck. Like how your diet called for sharper teeth.”

 

The mention has Dean unconsciously licking—presumably—his teeth behind the confines of his plump lips. Sam smiles at the sight, feeling a strange fluttery sensation in his stomach. It catches him off guard and makes him look away. He’s quickly distracted by the twinkling stars above them. “Wow.”

 

Thankfully it isn’t a cloudy night. Vibrant stars pepper the sky, leaving both Sam and Dean speechless for a good couple minutes as they admire the lights. 

 

“This is so beautiful,” Dean whispers in amazement, breaking the silence reluctantly. Sam glances over to appreciate the childish glee his friend is exuding. “I can’t believe I haven’t done this before.”

 

Voice equally as quiet, as if they are exchanging secrets, Sam shares, “This is one of my favorite things to do, but it’s so dangerous to go out in the dark that I can’t come up here very often.”

 

Dean briefly tears his eyes away from the stars to peer at the inky black water pooling around them. He meets Sam’s gaze. “I’ll protect you,” the shark states confidently. 

 

A warm feeling washes over Sam and he smiles softly with a hint of a blush. It’s clearly meant in a platonic way, of course—Sam knows that it’s what any good friend would say (if they happened to be as capable as Dean, physically speaking). It would be silly for Dean to go through all this trouble of providing for Sam and keeping him safe for him to suddenly throw it all away one random night by abandoning Sam here in the dark. But the shark’s vainglorious promise unintentionally sanctions a lizard brain response. Sam preens unconsciously, the omega in him purring, ‘what a good alpha; pursue him, entice him!’ as he fiddles with a damp lock of hair. “Thank you, Dean.” It comes out sultry, and Sam is abruptly aware of his actions. His hand shoots back into the opaque water violently before Sam looks away and coughs awkwardly. 

 

Although he’s staring determinedly up at the stars, Sam can hear the smirk in Dean’s voice. “Of course, omega. You can count on me.”

 

“N-Not just an omega,” Sam stutters, just for the sake of diverging the conversation.

 

“Never said that,” Dean huffs, presumably unhappy with the implication. “You’re also... A giant. When’d you get so big?”

 

Sam sighs. He composes for a second or two, relishing the peculiar feeling of brisk air tickling his bare skin. “I would say my... Nineteenth spring I filled out unexpectantly.”

 

The young mer’s tone must give something away, because Dean suddenly sounds apologetic. He spits out each sentence in quick succession. “Do they not like big omegas in Crag? I think you’re fine. Their loss, if you ask me. You’ve clearly got the whole omega thing down. What with the gratitude and... Hair thing.”

 

Huffing out a breath of laughter, Sam looks back down at his friend. “Hair thing?” he inquires with a tilted head.

 

“Y’know it’s, um.” Sam can feel a weak current hit his tail, so he can only assume Dean’s making hand gestures under the water. “Long and girly. Not that girly’s a bad thing, because like I was saying you’re an omega, so that’s a good thing.”

 

Sam contemplates ‘girly’ for a moment before understanding. “Oh, girly. You mean how female sharks have long hair?”

 

“I mean, yeah. But like how girls have long hair. Except a couple, I guess.”

 

Frowning, Sam quickly replies, “We have alpha, omega and beta. Mers—it’s not like girly or boyish. It’s... Alpha, omega and beta.” He’s only somewhat familiar with the idea of male and female from a elective course in grade school about general information concerning predators. It took a whole two weeks for Sam to wrap his head around the idea of sharks and their strange genders. 

 

Dean frowns right back at him. “Hold up. Lemme get this straight. You’re just... omega? You’re not a boy?”

 

Sam realizes that, to Dean, he’s probably the most similar atomically from the waist up with a male shark rather than a female shark. Even though his hair is shaggy, his breasts are rather flat and he’s not very petite in nature. Maybe objectively he’s more boyish, but Sam can carry pups. He could also sire if he so desired, but Sam doesn’t desire thatat all. “I am omega,” Sam agrees, understanding Dean’s confusion.

 

Dumbfounded, the shark struggles for words for the next several seconds. He seems to have given up subtlety out of frustration, blurting, “Do you have a pussy?”

 

The bluntness and intimate nature of the question makes Sam uncomfortable. He looks away. “That’s a pretty rude thing to ask,” he mutters, offended because of the disrespect of his privacy and chasteness. 

 

Dean back-petals very quickly when he realizes how upset he’s made Sam. “Fuck, I’m sorry, Sam. I’m just confused. That was rude, I’m sorry.”

 

Whatever Dean’s dad did teach him in the short time they were together probably didn’t include anything about social etiquette, so Sam is quick to forgive. “It’s okay,” he says reluctantly, meeting Dean’s regretful eyes. “I can carry pups, if that answers your question.”

 

Dean’s green eyes widen. The only way to describe the way he regards Sam is with awe, like Sam just expressed he was the son of Poseidon or something equally astonishing. Being looked at in such a manner disturbs Sam, as he is a humble creature. He doesn’t know how to defuse the situation so he averts back to the stars for guidance.

 

Whatever spell Dean’s been put under fizzles out when the young mer jerks. “I’m sorry. That’s just... Obviously not how sharks work.” He laughs forcibly, ashamed of his behavior.

 

“Yeah.”

 

It takes a good while of appreciating the stars before the awkward tension is long forgotten and the silence between them is comfortable. Sam captures a glimpse of Dean lost in the beauty of the upper world, expression almost as awe-stuck as when he was looking at Sam either. Almost. 

 

The idea of having nights like this at his fingertips, watching the stars with Dean and blowing each other’s minds with cultural and biological facts, pleases Sam to no end. What he’d give for this to be his life. The prospect is much more enticing than hypothetically returning to Crag, facing his colony that’s probably already mourned his death. This would be a wasted opportunity for spontaneity and adventure. Sam could live out in the wild with a shark! How many mers can say they’ve done that?

 

“Would you mind, Dean?” Sam asks quietly, breaking the silence. “If I stayed?”

 

Dean peers at him curiously. “Stayed?”

 

Sam’s only marginally scared of being rejected, so he sacks up. “With you. Forever.”

 

Surprised, the shark physically moves back a few inches. “You would stay with me?” Dean is gobsmacked, which makes Sam giggle. “Forever?”

 

“Well, until I run into a shark or something like that,” Sam answers teasingly, alluding to an early death. 

 

Dean smiles brightly at the young mer. He takes one of Sam’s hands into both of his. “I would love for you to stay, Sam. That would be... Awesome.”

 

Smiling in return, Sam’s about to verbally express agreement when he’s cut off by a yawn. He licks his lips sleepily. “Then you better get me back to our nest. I’m getting pretty tired.”

 

Beaming, Dean nods. “Our nest.” He gently tugs Sam underwater to begin the difficult journey back home.

**Notes for the Chapter:**

> i know i don't reply but i read every comment and they all make me blush! thank you all for commenting and enjoying my story. comments really make uploading feel real and modivate me to write ;)


	5. Chapter 5

**Notes for the Chapter:**

> I’m changing shark anatomy just a smidge, but don’t worry, I’m leaving the fun parts ;)

With Sam’s residence officially permanent, it isn’t long before Dean suggests moving out of their shabby, sorry-excuse-for nest. Or maybe it’s more of Sam’s idea, who has dropped hints about his unhappiness with the cave for days now. Either way, they reach an agreement about relocating.

“You’d be okay with being further from Crag?” Dean asks politely over breakfast one morning, clearly already having an idea of where they should go.

If there was anything in Crag that Sam had passionate attachment to, he’d have a different answer. As it is, there’s nothing he can thing of that he’d miss to extent of slipping into a depression. Karen comes to mind, but Sam knows it’d be better for both of them if he stayed gone. If Sam had the option to take Dean with him to Crag, he’d pick that. But sadly that’s not the world they live in, so Sam knows the only option he really has is to stay with Dean. If he wants to live with him, anyway.

“I wouldn’t mind,” Sam replies as he thoughtfully picks at his fish. Or one of his fishes. Dean’s been delivering more food as of late, bringing Sam double if not triple the portion size he’s used to. If Dean wasn’t so obviously proud of himself for his hunting skills, Sam would think the shark’s trying to fatten him up. “But how far were you thinking, exactly?”

Dean shifts excitedly from where he’s perched. “I was thinking we could go to my family’s old nest. It’s bigger than the one we have here.”

“As long as there’s room to decorate,” Sam says, equally teasing and serious. The plainness of their current cave has made Sam long for bright colors and unique furniture. “How long will it take to swim there?”

Dean purses his lips and thinks for a moment. “Only a couple hours. It’s... If I remember correctly, it’s close by another mer colony.”

The prospect of being near a foreign colony delights the young mer. He thinks about making trips into town to trade items in exchange for various pieces of furniture or decor. With such a long trip in front of them, they’re bound to come across some undiscovered seashells or maybe even something more intriguing. “Which one?”

“I couldn’t tell you. The only reason I know that Crag is called Crag is because of you.”

There’s only a few colonies that are ‘close’ to Crag, (the closest being an hour or two away) so Sam lists off them in hopes Dean will recognize one of the names. “Do any of those sound familiar?”

“Nada,” Dean shrugs, looking apologetic. “Why does it matter?”

“I’m just wondering where your family’s nest might be geographically. But you’re right. It’s not really that important.” Sam takes a big bite of his fish, catching Dean smile at the sight of his full mouth. Sam rolls his eyes and feels his face flush.

Dean looks away and scratches his full belly. “Well, we should leave after you’re done eating. That way we can get a few things set up before nightfall.”

Chewing thoughtfully, Sam then swallows and asks, “Are we bringing the, um, bed?”

“I was planning to,” Dean answers, coughing. He always goes a bit tense when they talk about their ‘bed’, seemingly because he’s ashamed he hasn’t been able to provide anything better. “Do you have any better ideas?” he asks softly, sincerely.

Sam runs through a few different options in his head before replying. “That depends. When you were little, did you ever see wood floating on the surface?” If Dean’s old cave is near an island of some sort, Sam knows how to drag a buoyant log of wood underwater and remodel it into pretty much anything. Well, as long as ‘pretty much anything’ is limited to a bed or dresser.

“I don’t think so,” Dean says, brows drooping.

“That’s fine. I’m thinking we could trade seashells for furniture.” Sam decides he’s not hungry anymore and silently pushes his leftovers over to Dean. The shark only waits for a final glance of assurance before scoffing it down.

Sam smirks at Dean while he unattractively stuffs his face with the bits Sam found too rubbery or discolored. Dean most obviously isn’t a texture person, instead he’ll chew and rip until he reaches something unchewable—in which case he’ll either _make_ it chewable or finally yield and spit it out. “Well,” Sam drawls, “we should leave after you’re done eating.”

Dean looks unimpressed with Sam’s jest, but the young mer feels thoroughly rewarded regardless and snickers.

 

Normally Sam’s able to travel any distance without complaint as long as he’s got good company, but right now—two hours in to their journey—he’s mind-numbingly bored.

“If you were a fish, what fish would you be?” Sam asks, swimming around Dean in graceful, wide circles as the shark swims in a straight line. It’s a very easy rhythm to maintain because Dean’s been going in said straight line for the better half of an hour.

Truthfully Dean barely knows the names of the fish in these waters, only really paying attention to the ones that are good to eat. “Uh, I don’t know.” He diverts, asking, “What do you think?”

Sam draws out a ‘hmm’ for a few seconds, the noise sounding mystical as he swims around Dean. “Oh! What about a barracuda? That seems about right.”

Apparently unfamiliar, Dean forces himself to ask, “What’s a, uh, barra—that?”

“Poseidon, they’re the scariest things. They come up and bite you. And when you try to get away they chase you. They’re so fast.”

Laughing wryly, Dean replies, “Annoying and persistent? Yeah, sounds like me. I’m not too scary, though, am I?” It’s said very good-naturedly but there’s still some underlying doubt in his tone.

To reassure his friend that there’s no unsaid tension over Dean’s species, Sam abruptly stops swimming and gently plops himself onto the shark’s back, his brown tail hanging off the side. Sam’s fin briefly touches the sand before it’s lifted off, Dean obviously adjusting his strength to accommodate the mer on top of him. “Oof!” Dean grunts.

“Oh, _terrifying_.” Sam scoots towards Dean’s dorsal fin before leaning down to wrap his arms around the shark’s chest. Sam hums again and decides he might as well he comfortable, resting his head on the back of Dean’s neck. “In fact... I think I’m... fainting...” he yawns dramatically.

Dean laughs, one of his hands coming to his chest to rest on top of Sam’s, the other carrying their ‘bed’. “Fainting or swooning?” Sam can practically hear the suggestive eyebrow raise in his voice.

“You wish,” Sam huffs, glad Dean can’t see the horrendous blush creeping up his face.

“What about you, then? What fish are you?” Before Sam can respond, Dean cuts him off. “No, wait, scratch that. I know exactly what you are.” He squeezes Sam’s hands. “My little pilot fish.”

 

When they finally reach Dean’s childhood nest, Sam is nearly asleep. After all, it’s time for their nap. Luckily Dean managed to carry him the rest of the way, showing no signs of physical distress or annoyance. _Like a good alpha_ , Sam’s brain unhelpfully chirps.

Dean also seems prepared to carry Sam all the way into the cave, but he’s stopped by the mer himself when he jumps off. “Hold on.” Sam rubs his eyes, looking intently at the cave about forty fins away. It’s a huge hole in the side of what appears to be a mountain, framed by thick kelp. A mountain that goes up, up, up, all the way to the surface. “Is this an island or a volcano?”

Following Sam’s eyes, the shark shrugs. “I never went up there. No reason.”

“We’ll have to check it out later,” Sam says, suddenly feeling a sense of uneasiness when he looks back to the cave. He finds himself reaching for Dean’s hand and lacing their fingers together for comfort.

Dean frowns at the young mer, tugging him closer. “If anything’s in there, I’ll take care of it.”

Sam nods, bangs falling into his eyes. “Okay.”

They leisurely swim to the cave, Sam pulling Dean even closer when they enter the mouth. He’s distracted, however, when he takes in the view. “ _Dean_...”

The cave isn’t slightly bigger than their old one, it’s overwhelmingly bigger. From what Sam can see, the open space alone is more than twice the nest size he grew up in. Stalactites hang from the ceiling almost as beautifully as a chandelier, covering the majority of the ceiling. Towards the floor of the cave, there’s stalagmites, slopes, and mesas, all surrounded by various types of sea plants. A few smaller caves littered around the walls, areas that would probably be considered personal rooms. What draws Sam’s attention the most, however, is the hole in the ceiling. It’s almost a perfect circle of rich, blue water, giving way to the sunny day happening above them. Sam’s left speechless by the beauty of it.

He turns around reluctantly, admiring the mystical way the ropes of kelp near the entrance almost provide something akin to a curtain. With some modification, this place could be transformed into a private oasis.

“Is it okay?” Dean asks quietly, gaining Sam’s attention. His unsure expression sobers the young mer, and he squeezes Dean’s hand.

“This place is... _Magical_ ,” Sam answers, looking away from Dean’s equally magical eyes to once again admire the cave. “I didn’t think... Why didn’t you tell me it was this big?”

Shrugging, Dean unlaces their fingers so he can inspect the smaller cave veins, as to ensure they’re the only occupants. Sam watches him cautiously swim to each one and peer inside. “It’s actually smaller than I remember.”

Now feeling far more safe than he did a few minutes ago, Sam preoccupies himself with swimming around and feeling the plants. Directly underneath the hole is a patch of sea lettuce, greedily soaking up the sun. Sam plucks a few pieces and munches happily.

“I’m actually surprised nobody decided to take over this place,” Dean muses, seemingly done with his inspection and catching up with Sam. “It’s completely empty.”

Sam looks up at the surface. “I’m surprised there’s no crabs in here. Or turtles.” Glancing at Dean, the mermaid curiously begins to ascend. Dean follows closely, silently miffed that he can’t breathe air and therefore cannot properly protect Sam in the upper-world’s environment.

Breaching the surface, Sam has a moment of complete panic where not only can he not breathe, but he can’t see. It passes very quickly, though.

The small pool is, in fact, surround by an island. Whether it’s a big island or not is inconsequential—it’s not like they could explore if even they wanted to. But nevertheless it’s an island, complete with sand and trees and sea grass. Or, well, Sam wonders if it’s now _land_ grass, since it doesn’t have the pleasure of being in the sea. “It’s gorgeous, Dean,” Sam says gleefully when the shark joins him, still only half of his head sticking out of the water.

Sam swims carefully to the edge of the pool, digging his hands into dry sand. It’s much cruncher and unpleasant when it’s dry. Sam doesn’t like it.

There’s a grassy hill a few fins from where the sand ends, and Sam can see large fruit trees growing at the peek. He’s only had fruit once or twice in his life—Sam can’t even remember what kind it was—since it’s such a rare delicacy in Crag, but Sam vividly remember how succulent the soft fruit flesh tasted. “There’s fruit trees, Dean!”

“Uh, Sammy?”

Snorting, Sam turns around to face Dean. “Don’t call me that. It’s just Sa—“ He cuts off quite suddenly when his eyes settle on the thing Dean was most likely trying to draw his attention to.

On the other side of the pool is what appears to be a skeleton of some sort of mutated creature. It rests in the sand peacefully, presumably it’s equipment surrounding it. The only things Sam is able to identify by name, however, is the butchered turtles and a large trunk half-buried in the sand.

“What is that?” Sam whispers nervously, frowning at the sight of the long-dead creature. Even though it’s been dead awhile, Sam can’t help but wonder what killed it, and if it’s still around.

Wanting to comfort his friend, Dean slips close underneath Sam and proceeds to wrap the mer’s arms around his chest, effectively giving him a dolphinback ride. “Not our problem,” he replies, ready to slip back under the water and put Sam somewhere more secure.

“Wait.” Sam bites his bottom lip. “I wanna look in the trunk.”

Skeptical but yearning to please, Dean slowly brings the both of them to the edge of the pool. Sam squirms off of him, taking a deep breath. He very carefully raises himself out of the water and onto land. It’s not as irritating as he imagined, once he’s fully out of the water. The sand is still dry and rough, but he hasn’t became instantly dehydrated, so it’s okay.

Still in the water, Dean’s rewarded with a rather spectacular view of Sam’s backside. Just like any mer, Sam’s lower back gives way to two plush buttocks that rest right above where his tail begins. As the young mer crawls towards the chest, his butt moves side-to-side sensually.

It’s not inherently sexual. After all, mers are more often than not completely uncovered. And pretty unashamed of it. Not that sharks are any different; not that Dean isn’t completely uncovered, too. But the shark’s nevertheless caught off guard by the image, his claspers tingling from within his stealth.

“No _way_...”

Dean violently jerks in the water at Sam’s voice, pulling his eyes away from the mermaid’s ass. “What is it? Are you okay?” He feels so helpless, defenseless, as he’s unable to protect Sam in any way as long as he’s on land.

Twisting so that he’s comfortably sitting in the sand, Sam reaches into the trunk, out of Dean’s view. He grumbles quietly until he hears a soft clinking noise.

Sam turns around with wide eyes, an open mouth, and two fistfuls of golden coins and colorful gems. “ _Treasure_.”

Dean’s fingers curl around the edge of the pool and he holds his breath, pulling himself upwards with the strength of his upper body. “Holy shit.”

Flabbergasted, Sam nods in agreement before turning back around to dig around in the trunk. “There’s a lot in here.” Although Sam isn’t one to steal, it’s quite obvious the dead creature won’t be needing this treasure any time soon, so he starts to dig it up. “This should do nicely to decorate our nest. Do you know which direction that colony you mentioned earlier is?”

Uncomfortable, Dean ducks back into the water to wet his gills. “I would bring you to the outskirts, but...”

“Could you wait there for me?” Ever since Dean’s became his permanent companion, Sam’s developed somewhat of a complex about traveling alone. Maybe it’s unhealthy, but Sam becomes very anxious when he thinks of being without his protective friend by his side. “Out of sight.”

“Of course!” Dean replies, watching Sam push the trunk towards the water. He moves out of the way, enthralled by the glittering jewels peeking out. “This might be blood money, Sammy,” he warns.

Sam scoffs, glancing again at the skeleton. “Let’s give them the benefit of the doubt. Maybe it was inheritance!”

“I don’t think anyone becomes marooned over an inheritance,” Dean points out, equally ready to claim the treasure as their own but suspicious about its origins. “But his lost is our gain!”

The trunk creates a big splash when it enters the water. It takes a moment or two to sink, but it eventually does. Sam and Dean both watch it gently fall onto the sea lettuce, the loose treasure staying more or less inside the trunk.

“Maybe, though...” Dean thinks of their pile of cloth he’d placed in one of the smaller cave veins. “A nap before we head out?”

Sam answers by shuffling back into the water, more or less throwing himself into Dean’s arms. The shark gladly catches him, hissing in sympathy at the sound of Sam’s brown scales rubbing against the sand. “Look how lazy you’ve made me,” Sam yawns, hugging Dean tightly.

 

After a short rest, Sam follows Dean to the apparent location of this mysterious colony, carrying a small amount of gold coins wrapped in cloth. The shark is reluctant at times, looking around as though he’s not completely certain they’re going the right direction. Sam can’t blame him, though. He’s impressed Dean knew how to even get to his family’s old nest. Maybe it’s instinctual, a failsafe in his hindbrain to go where he was pupped and hope for the best. Sam can’t relate—He probably couldn’t make it back to Crag if his life depended on it. Not without Dean’s help, anyway.

As they swim, Sam pipes up curiously. “It’s okay if you don’t wanna talk about it, but... Doesn’t it bother you? Being in your family’s old nest?”

Dean had expected this question to come up earlier, so now it surprises him that Sam’s finally asking. He takes a deep breath, uncomfortable with sharing his doubts and emotions. In the wild, that kind of stuff makes you vulnerable. And being vulnerable gets you killed. But Sam wasn’t raised that way, so he expects heartfelt answers. Dean tries his best to abide by that, but he’s never been the heartfelt sort. “I wasn’t there much of my life,” he admits quietly. “I remember being there... With my mom, my dad. The place itself wasn’t ever important to me. Just who was there with me.”

Sam is silently impressed with Dean’s honesty, reaching out to rub the strong plane of the shark’s back for comfort. “Didn’t you tell me sharks don’t really nest?”

“Yeah. Normally it’s love ‘em and leave ‘em, but... I dunno, maybe they were really in love. I never asked Dad why.”

The thought of two sharks being so infatuated with each other that they decide to settle down and mate together like two mermaids would swells Sam’s heart. It quickly deflates when he remembers how their story ended, however. He pulls his hand away, frowning. “It’s a really beautiful nest, Dean. I like it very much,” the mer says in hopes of distracting Dean from his slump, appealing to his provider instincts.

“I thought you would. You’re very high maintenance,” the shark teases.

Sam pulls on Dean’s ear in retaliation. He’s amping up for a comeback when he notices a large statue in the distance. Sam clutches the makeshift bag of coins tighter, squinting curiously.

Dean’s also skeptical, grunting, “The hell is that thing?”

As they approach the statue—which is more so an engraved stone column—Sam’s memory is jogged. “I think...” He swims a bit faster, Dean keeping up with him easily. “Oh, we must be close to Pandemos. This is Aphrodite,” Sam explains, gesturing to the engraved image of a human riding a land creature.

“Sammy,” Dean says slowly, tapping their bag of treasure. “Do you think that skeleton was... a _god_?”

Sam thinks back to how the mutated skeleton had what must of been two legs, very alike to many of the gods. “A punished god,” he mutters, thinking of how it was trapped on a island. “I can’t imagine a god dying under such silly circumstances. There was fruit and sea water. What else could anyone need, even a god?”

Dean curiously traces the outlines of Aphrodite‘s beautiful hair. “Maybe it was a thieving demigod, sent away to perish alone with their riches as a lesson of greed.”

“You’d be a good storyteller,” Sam compliments, giggling as he bumps shoulders with the shark. “Pandemos can’t be too far from here. Could you wait for me by this column? I won’t be long.”

More than hesitant to leave Sam alone the rest of the journey, Dean scowls at the sandy ground. “Since I have to. Please be careful, Sammy.”

With a confident smile, the mermaid clutches his riches even tighter and begins swimming straight away from the column, from Dean. There comes a point where he’s so far away that his companion is only a foggy image in the distance. It’s very reminiscent of their first departure, all those springs ago, and Sam feels a strong wave of déjà vu.

Thankfully, it isn’t very long before Sam comes across a tall fence made out of wooden beams. He quickly locates what appears to be the entrance, waiting outside patiently for one of the guards to notice him. This must be Pandemos. He remembers reading about this ally colony, blessed by Aphrodite with plentiful resources and notably fruitful matings. Besides the heavy security, the vibrant flags waving on top of the fence give it away.

“Καλησπέρα, traveler!” an armed mer calls out, staring down at Sam from his perch. “State the business you have with Pandemos!”

Sam stifles a laugh at the guard’s serious tone. Guards are required, but he’s always thought fences and gates made little sense to have. Maybe from within it provides a sense of security, but in reality it’d be very easy to swim over. “I come for trade,” Sam shouts. “Unarmed,” he adds.

This must be a good enough answer, because shortly after the guard darts out of view, the gate opens. Sam swims inside, greeting the guard properly before venturing further into the colony.

It’s not too dissimilar from Crag other than the fact they are indeed... Blessed. Each nest he passes is so grand they could only be referred to as houses. It’s a very modern colony filled with temples and shrines dedicated to Aphrodite. Sam’s always been more loyal to Poseidon than any other god, but he does a quick prayer as he passes to pay his respects.

Eventually Sam reaches their marketplace, the omega in him immediately drawn to the plush furs and blankets section. But he’s here for basic furniture, there will be time for luxuries later.

Sam scans the shoppes for a moment before spotting some bed frames. As he’s checking out the items, he feels the familiar sensation of cramps in his lower abdomen. Ignoring them, Sam calls over a vendor and inquires, “Does this come disassembled?”

**Notes for the Chapter:**

> Fun fact: this story was originally a one shot. Can you believe that? It got WAY out of control.


	6. Chapter Six

**Notes for the Chapter:**

> Sorry for the late upload. I usually post on Saturdays, but I’m not sure when the next update will be now that I’m behind... oh well, enjoy this one!!

 

It takes an entire week to move the majority of furniture into Sam and Dean’s new cave, and even that isn’t enough time to get _everything_ done. Dean doesn’t voice his opinion, but he thinks it’s insane how much stuff the mermaid drags inside to ‘improve the aura’ or ‘spruce up the place’. If you ask Dean, he thinks it was perfectly spruced before. Except maybe the bed situation, which has been mended. Now they sleep on a larger, sounder bed that’s actually meant to be slept on. Dean said nothing about the fact they could afford two beds; said nothing about the fact they could sleep in separate rooms. Although it’s distasteful, Dean can’t help but enjoy their intimacy, even if it’s platonic. Sam is... nice to look at, nice to hold. Dean is only slightly guilty that he feels this way about his friend.

Dean now watches from their couch, ready to jump in any moment and assist, as Sam fiddles with the large kelp that frames the entrance to their nest. He’s intent on making them serve as a curtain of sorts. For privacy reasons. Mers are so strange.

Swimming back to admire his work, Sam excitedly looks back at Dean and points to the kelp he’s manipulated. “It’s done! How does it look from back there?”

It looks like a cave entrance obscured by kelp. “Awesome,” Dean says, clicking his tongue and giving a thumbs up.

All of a sudden, Sam makes a soft sound of distress and the smile leaves his face. Dean almost asks what’s wrong, but this has been going on for the past few days, and he knows exactly what’s wrong. “You should come lay down, Sammy.”

Sam nods, swimming slowly down to meet Dean on the couch. “I hate this,” he grumbles, curling up next to the shark. “I feel so gross.”

Just a minute ago Sam was all optimism and joy. These mood swings are nerve-wracking. “It could be worse,” Dean reminds, for a lack of anything better to say. “Is there anything I could do for you?”

“My back hurts,” Sam whines, maneuvering his body so that he’s splayed across Dean’s lap. He looks up pitifully and flashes his dogfish eyes.

Dean looks around the cave that’s been thoroughly decorated before peering down at the young mer. “You’ve domesticated me,” he complains, starting to rub Sam’s sore muscles.

Giggling, Sam muses, “I wonder what people would say if they knew I was with you.”

“Nothing good,” Dean grunts, rather sorrowfully.

“Well, I don’t care what they think. You’re the greatest friend I’ve ever had,” Sam whispers, as if it’s a secret. Dean can’t help but feel like he’s a secret to be locked away, and his heart simultaneously swells and drops. He wishes he was a mermaid like Sam. That they could be together. If he was an alpha mer, things would’ve surely progressed differently.

“Same here,” Dean replies softly, his free hand coming over to play with Sam’s hair. The mer makes a contented sound at the sensation, and Dean basks in the feeling of being needed. What else is he really here for, if not to take care of Sam?

 

Exactly twelve hours later, Sam wakes up even more sweaty and gross than the day before. His slit is throbbing painfully, indicating to him that it’s pertinent he find a mate soon to act as a balm for his heat. Obviously that isn’t going to happen, so Sam writhes and groans unhappily when he thinks about how he’s going to suffer alone. _Again_ , just like every spring before.

“Sammy?” Dean inquires sleepily, rolling over to check on the young mer. He was instructed to sleep as far away from Sam as possible, who expressed he felt too yucky for their nightly cuddle.

“My heat,” Sam croaks, clutching his abdomen. “Soon.” He’s too distressed to offer any further explanation, so thankfully Dean understands completely and doesn’t force him to provide one.

Dean isn’t an alpha, but he’s a shark, and sharks have a remarkable strong sense of smell. Sam’s pheromones are throughly stinking up the place—but in a good way. In fact, Dean thinks it smells mouthwatering, the scent much more potent than when he was little more than a pup. It’s as if Sam’s body finally knows what it’s doing, trying to entice a mate with strategically excreted smells. Dean considers comforting Sam with the fact at least he doesn’t smell bad, but since the mermaid looks rather close to peeling off his own skin out of frustration, Dean holds back.

Wanting nothing more than to please, Dean offers, “Would you like me to go find us a lobster for breakfast? Maybe some of that sea lettuce you love so much?”

“Mm,” is Dean’s answer. He decides to take that as a yes.

“I’ll be back soon.” Dean rises out of the bed, looking over Sam’s prone form. He’d be damned if something caught the mermaid’s heat-smell and decided it fancied a quick roll or an easy snack. “I know you’re hot but you gotta bundle up, Sammy.” Dean wraps a blanket around Sam in an effort to stifle his scent. Sam only whines in response.

As Dean is gone on the search for lobster, Sam bites their blanket to help with the pain. He’s achey all over and so empty. Slick positively gushes from his slit when he allows his mind to wonder to mating. This heat feels much different than his previous ones, as if he’s somehow more fertile and desperate because of it.

Sam distantly thinks about the prayers to Aphrodite he’s been making during his visits to Pandemos. Maybe the goddess misinterpreted his thanks and ‘gifted’ him with... This.

The young mer manages to hold out a few more minutes before the ache in his slit becomes too much to bear. Shamefully, Sam reaches under the blanket and easily finds his leaking sex, slowly introducing his fingers.

Relief is short-lived, however. Almost immediately Sam’s body decides it’s not enough, and he starts crying. He can’t help it. The hormones and desperation are really getting to him.

Pumping his fingers furiously, Sam tries to sate himself but with no success. He has to suppress the urge to cry out for an alpha to help him, to breed him and take away the heat.

Sam sniffles. Of course, it wouldn’t _need_ to be an alpha. He’s known many beta-omega couples in Crag. Some of which have spilled their private life, implying there’s no need for alpha when you have an enthusiastic partner. He remembers giving pause, wondering if the facts about only alpha pheromones being able to balm a heat were simply propaganda or an old wives tale.

In hopes that an imaginary mating might provide relief, Sam continues to pump his fingers and thinks of a strong alpha pinning him down, filling his cunt with seed.

Sam needs a face to go with the sensations, though. His mind subconsciously drifts to fluffy blond hair, tan muscles littered with freckles. Maybe green eyes, too. And a perfectly symmetrical face—that’s important, means the alpha is a product of pristine breeding and undoubtably in good health...

“Dean,” Sam cries, removing his fingers as he’s only amping himself up even more. Poseidon, he’s never been this horny in his entire life. “ _Dean_.”

Body clearly intent on driving him to mate, Sam’s cock springs free of his stealth. He sobs harder, wrapping his free hand around it and pumping. Nothing helps.

It isn’t very long before the shark returns, bearing not only lobster but fish and vegetation. Dean barely managed to catch the fish, his mind repeatively reminding him that Sam is defenseless and alone. That was more than a good motivator to hurry his ass up.

Entering their nest, Dean stiffens when Sam’s heat hits him even harder than earlier. By the time he’s outside the small cave that leads to their bed, it’s so strong Dean’s sure he can actually taste Sam’s slick. “Sam?”

Dean’s deep, alpha-y voice triggers more slick. Sam’s cunt is completely exposed to the outside world, as it’s normally sealed and hidden by a layer of scales. Because he’s so aroused, it’s taken the liberty of showing itself and it’s pink insides. “Dean, alpha,” Sam moans, out of his mind with lust. He tosses the blanket to the cave floor, presenting himself to the shark.

Surprised, Dean drops their breakfast. He’s loss for words, drawn instinctively to Sam’s leaking cunt. His curiosity urges him to investigate the strange and unique sight of a vagina and cock attached to the same creature, while Dean’s claspers urge him to _bite_ and _take_.

Reflecting on the word ‘alpha’ snaps the shark out of it. Sam isn’t thinking straight, and it’s Dean’s responsibility to control the situation. “Sorry, Sammy. Not your alpha,” he mutters morosely, picking up the blanket and trying to cover up Sam’s genitals. _Plural_. Genitals. It’s one thing for Sam to admit he has a pussy, but it’s another thing to actually _see_ it.

“No!” Sam growls, abruptly sitting up and pushing away the fur blanket. It was expensive, so Dean yields and allows it to fall to the ground once more in favor of letting Sam ruin it due to wrath. “Mate. Please!” He presents himself again, lying horizontal and trying to make himself as alluring as possible.

“Sam, this is just your heat talking,” Dean tries to explain, realizing there’s no point when Sam’s hands shoot out to apply pressure to the slit below his belly button. “Hey! Stop!” He catches the exploratory hands. “You’ll regret this in a few days.”

“Won’t,” Sam insists, sounding like a drunk caveman. “Want you. So _long_.”

Heart surging, the shark frowns. “Really?” Dean can’t help but want to believe the mermaid’s words, having pined after him for literal years, even when they weren’t in contact. The feelings were confusing at first, but now it’s obvious to Dean that he’s in love with Sam. He wants to mate him, be with him every day. Is it possible Sam has been craving that himself?

“Really,” Sam cries, feeling so empty and rejected on top of it. He pulls away from Dean and makes a show of spreading open his cunt. “Want you. So bad!”

Between the slutty picture Sam makes and the pheromones, Dean can’t take it anymore. Both of his claspers slip excitedly out of his slit. He dives forward to grab Sam by the waist.

When he looks up at Sam’s lust-blown eyes, Dean pauses. He’s making the same face Dean reckons he made when he first discovered the mermaid was hermaphroditic, rather than a male. “Sammy?” Is he already regretting their coupling before it even begins?

Sam reaches down and tries to wrap his hand around Dean’s claspers. Even Sam’s big hand is too small for the job and the young mer gasps loudly. Sobering up a little, he breathes, “You’re... There’s _two_ , Dean.”

At Sam’s touch, Dean’s claspers swell even more. He pants heavily, fighting against himself to just shove one in and begin thrusting. “Shark thing,” he grunts.

Normally, Sam would have a million questions and take it upon himself to understand why Dean has not one, but a set of identical reproductive organs. But right now all he can think of is how he’d love Dean to shove both of his cocks inside and have his way with him.

At a desperate whimper, Dean decides to put Sam out of his misery and ducks down to bury his face in the mermaid’s cunt. His right hand trails up to loop around Sam’s flushed cock, stroking it.

“Dean!” Sam yelps, bucking up accidentally from the pleasure. Dean takes the abuse in stride, smirking as he sucks and licks the inside of Sam’s cunt.

It tastes just as amazing as it smells, the slick harboring a heady, sweet but slightly sour taste. Dean loves it, scarfing down Sam’s juices while trying not to nick the sensitive parts with his ultra sharp fangs. He pulls back to focus on the mermaid’s clit, lapping at it. “Taste so good, baby,” Dean purrs in between licks.

Squirming, Sam’s hands find Dean’s hair and his fingers bury themselves in the wavy blond strands. “Uh, don’t stop!” He convulses after a few more sucks and pumps, his cock ejaculating into the water as the cunt Dean’s feasting on spasms around his tongue. “ _Fuck yessss_!”

Dean doesn’t quit licking until the mermaid is begging him to stop, too sensitive to continue. He pulls back and loudly slurps as he cleans his face of remaining slick. Sam groans at him, cock giving a valiant twitch.

“Feel better, sweetheart?” Dean rumbles, pupils huge. Sam instinctually grimaces at the sight, recognizing the dilation as similar to when Dean was hunting him. The shark soothes his worries with his cool hands, rubbing Sam’s taut muscles. “Shh, I’ll take care of you...”

They cuddle for some time before Sam’s nagging heat has him once again insatiable. His cock is still hard, giving him no break. When Dean grasps it again, Sam’s moan echos throughout the cave. “Breed me, Alpha,” he whimpers. “Fill me. Please!”

Dean gives the omega a sweet kiss, tongue infiltrating his mouth. There’s no battle for dominance—Sam immediately submits, letting the shark plunder as he desires. As Dean’s sucking carefully on a plump bottom lip, he grasps his bottom clasper and aligns it with Sam’s needy cunt.

Wanting to watch Sam’s facial expressions, Dean pulls back and sinks in his clasper. They both groan loudly when he’s completely sheathed. Dean hasn’t indulged in a tight orifice in awhile and Sam’s never had sex before, so it’s an intense sensation for both of them.

“Dean,” Sam whispers, looking like he’s about to cry. “So full...” The mermaid looks down and is internally confused to see Dean’s top clasper obscuring the sight of his penetration.

Full doesn’t begin to describe the plethora of feelings shooting through Sam. He’s sure this is the epitome of pleasure, of being an omega. Finally, after so many years spent mateless and unsatisfied, Sam’s found a partner. Would this have ever happened any other way? Even in Sam’s heat-fogged mind, he can’t think of anyone he’d rather have than Dean. Dean might not be an alpha, but he more than qualifies as mate material.

They won’t be able to fully bond as mates, as a mermaid pairing would be able to. Traditionally mating is official once penetration has been achieved, pre-seed introducing itself to the omega’s core and binding the two together forever. Sam has heard some mers claim this can be thwarted by contraceptive-like methods, but the idea is utterly repulsive to him. If that is their future, mating mindlessly without minding the consequences, Sam doesn’t want to be a part of _any_ colony.

“So pretty speared on my clasper, Sammy,” the shark pants, leaning down to give Sam a multitude of eager kisses. It’s clear Dean is also losing himself, as the kisses lack any sort of finesse or pattern. “Fuck, you’re so tight. My pretty little mermaid.”

Whining in response, Sam wiggles his hips back and forth expectantly. His hand meets Dean’s where it’s wrapped around his cock and persuades him to continue stroking. “Uh-huh, yours, alpha.” Sam uses all off his energy to briefly sit up and kiss Dean’s nose before falling back down. “Breed me, please.”

“Oh, you wanna be _bred_ , omega?” Dean grins toothily, a terrifying display of his teeth. He releases Sam’s cock in favor of gripping the mermaid’s hips tightly. “I’ll breed you, then.” With nothing more on his mind than the simple task of filling Sam with his semen, Dean begins to thrust at a brutal pace.

Sam is equally enthusiastic, pumping his cock as Dean drills into him. “Yes, yes,” the mermaid cries out, basking in the feeling of delicious pressure against his cervix. It fills so good, simultaneously snuffing the heat and fanning the flame inside him. “Don’t stop!”

With no intention to, Dean thrusts in even faster. Sam seems to appreciate the extra effort, doing his best to meet the shark’s thrusts in his weak state. In tune with his instincts, Dean’s mouth finds it’s way to Sam’s shoulder, itching to bite down. The sight of the silvery scars Dean’s left there before deter him. He has to remind himself that Sam isn’t another shark that he can hold down and bite, he’s a delicate mermaid made to be coddled and pampered. Dean manages to relocate his mouth to Sam’s and busies himself with making out.

As Dean decides to leave a few hickeys on Sam’s neck, one of the young mer’s hands catches Dean’s top clasper. Sam rubs his thumb all over the head in hopes to hear the shark moan. He isn’t disappointed when Dean begs for more. Sam grips the clasper more securely and jacks it off as if it were his own. He would attempt to wrap his hand around both their cocks, as they are pretty much rubbing together anyway, but Dean’s thrusts are too quick and unpredictable for Sam to keep up.

“Alpha!” Sam screeches in pleasure, eyes falling shut. Between the ruthless battering of his cervix and Dean’s body rubbing against his cock, Sam feels another orgasm creeping up on him. “Gonna come again, alpha!”

Whipping his head back in a way that can’t be good for his neck, Dean licks his lips and grunts in agreement. “Me too, Sammy. Come for me. Wanna see you gush all over my clasper.” To aid Sam, Dean slows his thrusts so he can situate his thumb against the mermaid’s clit, picking up the pace again when it’s positioned correctly. “Do it, baby.”

Sam delivers, letting go of Dean’s cock in forgetfulness as he screams. His cute little cock pulsates as it did before, his useless sperm shooting into the warm water around them. Dean feels Sam’s cunt squeeze tightly in an effort of milking his seed. Dean’s only a hair away from blowing his load by the time Sam comes down from his high.

The omega chirps unhappily when he notices how flushed and horny Dean still is, reaching down to polish his top clasper. “Breed me, alpha,” Sam requests quietly, calmly. That’s what does it.

“ _Mine_.” With no more than three aborted thrusts, Dean moans loudly and comes deep into Sam’s cunt. “Fuck yes!” Sam watches Dean’s top clasper shutter and come, squirming when he feels hot cum fill him below, courtesy of Dean’s bottom clasper. “Mm...”

With half-lidded eyes, Dean drops the majority of his weight directly on top of the big omega, still inside him. “Yes...” he purrs, wrapping his arms around Sam to cuddle.

Sam doesn’t mind the weight. In fact, it makes him feel rather protected. “Dean,” the mermaid whispers reverently, feeling sleepy himself.

Dean presses a loving kiss to Sam’s temple. “Sleep, baby. I’ll...” Whatever promise the shark was about to make is broken immediately as soft snores cut off his speech.

Giggling, Sam hugs Dean back. Alpha or not, Dean’s seed seems to be acting as a effective balm. Sam feels sated and high on endorphins. He closes his eyes for only a moment before falling into a deep slumber.

 

Many hours later, the mermaid awakes to find himself alone in bed. Sam yawns at the discovery, wondering if Dean’s out getting them breakfast.

Mid-stretch, Sam remembers their early morning activities, freezing.

 _Oh Poseidon_ , Sam thinks in panic, _Dean and I mated. We’re mates!_ The thought is just as excited as it is worrying. Are they really mates? Sam doesn’t feel much different than he did a week ago, mate-wise. Other than the fact he’s not feeling his heat anymore. Is that a sign? Sam’s heat is gone, does that mean they managed to mate as two mermaids would?

“Sammy?” Dean calls out from the living area, hearing the young mer’s stressed breathing. “Uh, are you...?”

Sam has a different reaction than Dean was prepared for, shooting off the bed and embracing the shark with a death-grip. “I’m so sorry!” Sam whimpers. “I didn’t mean—I’m sorry, Dean!”

Confused, the shark rubs Sam’s quivering back and frowns. Sam just holds on tighter and tries not to cry. “No need to be sorry, Sammy. It’s... Me who should be apologizing.” Sam shakes his head in disagreement and speaks over Dean.

“I took advantage—“

“I coerced—“

They both cut themselves off to hear the other talk. Dean tries not to chuckle when neither of them speak up again. He nuzzles the side of Sam’s neck, thinking of how upset the mermaid is and wondering if he’s ever going to be allowed this close again. “Don’t be sorry,” Dean whispers soothingly. “You have nothing to apologize for. You’re in heat.”

“ _Was_ in heat,” Sam mutters, burrowing closer to the shark. “I still should’ve known better than to taunt you like that...”

Dean scoffs, pulling back enough so they can look into each other’s eyes. “What part of heat do you not understand? You couldn’t even swim right you were so out of your mind! And I...” He sighs, looking away shamefully.

Considering how Dean is holding him, Sam realizes that his friend isn’t showing any signs of being disgusted with him or his body. He remembers foggily how Dean gave into his requests when he had expressed wanted to mate with Dean before the heat hit. Have they been pining for each other this whole time?

Sam cups Dean’s face hesitantly with one of his hands. The shark turns to look a him when the mermaid’s thumb presses curiously against his lips. “Dean,” Sam whispers, annoyingly bashful for someone who he’s literally been inside of. Following his gut, Sam surges forward and presses their lips together.

Dean immediately melts into the kiss, humming. Their eyes fall shut and they exchange careful, questioning kisses until Dean forces himself to pull away. “I regret how it happened, but I don’t regret that we did it,” Dean admits selfishly.

“Me too,” Sam all but squeaks, hand falling to run over Dean’s strong arms. “I love you.”

While Dean detests vulnerability and emotional moments such as these, he knows it’s of the upmost importance to be honest. “I-I love you, too,” he whispers so quietly Sam has to watch his lips to decipher the message.

“ _Dean_...” Sam pecks his lips before burying his face in the shark’s muscular neck.

They hold each other for awhile, processing. Everything has changed, yet nothing all at. Dean has always acted like a doting alpha mate, and Sam has always clung to Dean like a bonded omega. The only thing they’ve really added to their relationship is sexual intimacy.

To be sure, Dean asks softly, “Is this okay?”

“More than okay,” Sam answers instantly, voice muffled as it disappears into Dean’s tan skin.

“You want me to help finish your heat?”

The mermaid pulls away and looks down at his tail, noticing how both of his sexual organs are once again hidden. Dean appears to be in a similar state. “It’s gone... I think.” Usually his heats last a few days, and even during his spouts of clarity he’s still horny. But right now Sam is put off at the thought of sex. He’s had enough of it for now.

“But... It lasted barely a day,” Dean states, confused.

Sam smiles shyly at the shark. “Your seed sated me...” He nuzzles underneath Dean’s chin. “ _Alpha_.”

Accepting the strange answer, Dean kisses the top of Sam’s head. “Lemme go grab you some food, Sammy. You outta be starving.”

As if on cue, Sam’s tummy rumbles. “That sounds like a good idea.”

**Notes for the Chapter:**

> ;)


	7. Chapter Seven

**Notes for the Chapter:**

> Not proofread, sorry about that. Also I’m going on vacation soon so I’m REALLY not sure when the next chapter will be. It’ll come eventually though, I promise :)

For the better half of his life, Sam has been looking forward to mating with an alpha. Out loud it sounds pretty cheesy, at least to anyone who isn’t a romantic like him. But in truth it’s always remained a delightful fantasy Sam’s indulged himself with when he was feeling particularly lonely. Now, watching the twinkling sky with Dean from their private oasis, the mermaid muses over how he’s found his alpha in the most unlikely candidate.

“All the stars in the sky couldn’t ever compare to the beautiful freckles painted across your cheeks,” Sam declares admiringly, fingers brushing lightly over Dean’s face.

Dean purses his lips. When he doesn’t respond immediately Sam turns away, knowing the shark isn’t one for overtly romantic gestures. He seems to just put up with it for Sam’s benefit.

The silence is broken by the almost undetectable sound of bubbles. Sam all but gasps when the smell invades their space. “Seriously?” he groans, pulling away and covering his nose.

Laughing at him, Dean replies, “You gotta expect me to compensate somewhere, Sammy. You’re giving me no choice here.”

“And you ruined the moment,” Sam sighs, crossing his arms with a scrunched nose. Truthfully, the smell is fleeting and minuscule, but Sam _is_ disgusted and hopes his reaction will deter Dean from repeating this. Judging by the shark’s amusement it probably won’t.

“I know I’m unreasonably handsome, but please hold back on the sappy ballets. I came up here to stare at the sky with you, not be wooed like, uh... Like a—“

“Omega?” Sam offers, smiling in despite of his best efforts to remain annoyed. He swims closer and uncrosses his arms. “My pretty little omega?” He blindly reaches under the dark water to find Dean’s waist, trailing the hand down to squeeze his butt.

Dean jumps away, there’s no other way to describe it. His glare is almost enough to make Sam consider his safety. “ _No_ ,” is all he says—growls—like a real alpha would at the implication. Perhaps even more aggressive than a real alpha. That’s probably the shark in him showing.

To aid in the apparent ‘compensation’, Sam angles his head submissively and looks up from under his wet lashes. “Sorry, Dean.” He shuffles forward and presses the top of his head under Dean’s chin. “Know you’re my big, strong _alpha_.”

Huffing, Dean accepts the apology and encases the young mer in his arms. “That’s better...” He kisses the top of Sam’s head gently. “You up for a late night snack? You didn’t eat much today.”

“No, I’m fine. I told you before, I’m pretty sure that fish was rancid.”

“Tasted fine to me,” Dean sighs, caught up on the fact Sam hasn’t been eating very much the past few days. It’s been worrying him more than it probably should. It isn’t like Sam’s properly sick or anything, he’s just not been enjoying his normally favorite meals. “I’m stuffing you full tomorrow.”

Sam snickers, pressing teasingly against Dean’s sheath. “How about you stuff me full tonight?”

The shark snickers right back and tilts Sam’s head up so they can share a heated kiss. “Now _that‘s_ what I call romance.”

 

TWENTY-FOUR YEARS AGO

“Daddy?” a reluctant pup inquires, trying his best to resist pressing against his father in trepidation.

Said father looks away from the sand bed where he watched a fish peer out before realizing it’s mistake and disappearing once more. “Yes, Dean?”

Dean swims just a bit further away from his dad and tries his best to disguise his wariness. “What’s that thingy?” he asks quietly, pointing at a strange creature far away—but near enough to garner Dean’s attention.

“That’s a jellyfish,” John answers immediately, instinctively reaching out to put his hand on Dean’s shoulder and guide his son away. “They’re not good to eat, Dean. Not good to touch. Remember that.” He rubs Dean’s hair fondly, proud of his son to recognize a threat when other pups would swim right up and discover the threat themselves.

Beaming under his father’s affection, Dean observes, “There aren’t any other fishies, daddy.”

“Not with you talking up a storm, smart boy,” John says playfully, scooping up Dean as his son wiggles and laughs. He shushes him gently. “How about we find a school and you try to grab something for momma and Sammy?”

“Can I?” Dean whispers in excitement, restless in his father’s arms as they travel towards the area John usually catches them food.

John quiets his son again but nods. It isn’t very long before he spots a small school congregating around a mossy rock. “Hunting is about the element of surprise,” the shark whispers softly to his son. “You must be quiet, quick, and _never_ hesitate.” John decides he’ll elaborate when Dean’s older. He doesn’t expect the pup to actually manage to catch a fish on his first try.

Free from his father’s grasp, little Dean swims quite near the school, but not near enough to warrant worry from the ignorant fishes. Dean clenches his tiny fists carefully, his ultra serious, calculating face brings a smile to John’s. After a minute of consideration, Dean darts very suddenly towards the swarm of fish and hones in on his instincts subconsciously.

When the school scatters, John is more than surprised to see his son holding a panicking fish. Dean forces himself to hold onto the fish tighter to compensate for it’s struggle. He does so reluctantly, but manages to snap it’s neck before John approaches.

“You’ve caught one, Dean!” John astonishes, searching for words. The shark pup looks overjoyed, wiggling his tail mindlessly.

“Can I give it to Sammy?” Dean requests immediately, holding his prize close.

The adult shark chuckles with a nod. “Of course you can. It’s time we got back, anyway. I’m sure Sammy misses you.” Sam and Dean have been close to inseparable since the former’s birth, surprising both of their parents. Both John and Mary were both worried about Dean’s reaction to the new baby not only because some children detest the idea of siblings but because little Sammy turned out to be a mermaid, like his mother. Dean took to Sam like a proper nestmate, however, only questioning the difference between their tails on a single occasion. As a pup, it’s easy to accept that ‘Sammy is a mermaid, just like momma’ even though to anyone older it would seem unspeakable bizarre. If you asked John five years ago if sharks and mermaids could breed, he’d have said the idea was preposterous, but look at him now.

“I can eat his leftovers,” Dean continues as they make their way back to their nest. “Sammy’s so small he can’t eat very much, you know. So I’ll eat the rest for him.”

John laughs at his son’s genuine antics. He’s an absolute whale when it comes to food, sucking in whatever you give him whether it’s minuscule or a large portion. Mary’s tutted at him multiple times for his table manners—or lack thereof—but Dean still prefers to eat as if he won’t be able to ever again. John thinks it’s endearing. Mary thinks John’s promoting bad habits. Dean’s only a pup, though. He’ll grow out of it surely.

They return to their nest promptly. The sound of Sam’s cries can be heard from outside the entrance, thus Dean swims hastily inside to find his little brother and soothe his cries. John trails behind him without a sense of urgency.

John joins Dean in Sam’s nursery, confused to see that Mary is not already rocking Sam in an effort to pacify him. That or literally pacifying him with one of her full breasts. He briefly watches Dean cradle Sam—now content and flashing a gummy smile—before leaving his sons to search for his mate.

“Mary?” John calls with a frown.

There’s no answer, just the muffled sound of Dean blabbing to little Sammy about how he caught his first fish. John throughly searches their large nest, growing more frantic by the second when his efforts prove fruitless.

She wouldn’t have left Sam here by herself, even if it was an emergency.

John’s exhausted all of his options when he realizes there’s a microscopic chance she’s sunbathing in the small pool they have above them. He doesn’t see her tail sticking into the water, but that doesn’t mean she isn’t sitting on the beach.

As he swims upwards, John recalls a rather happy memory of Mary crawling out of his reach on the shoreline and fingering herself teasingly. It placates his nerves, if only for a little.

Before meeting Mary, John has hunted and brutalized countless mermaids for their flesh. He’s ripped apart people to the point of unintelligibility. He’s seen intestines, bones, organs. He’s _eaten_ them.

But nothing, absolutely nothing in the entire sea could’ve prepared him to find Mary dead ashore, still gushing dark red blood and bearing the signs of a shark attack.

Time becomes obsolete when one finds their greatest love dead. John spends what might’ve been minutes simply staring at the corpse. A million thoughts are running through his head. _Who has done this? Why did they invade my territory? How could this happen? What am I going to do? Oh, Mary, our pups, what am I going to do?_

John’s been long jealous of Mary’s ability to breathe air. If only for this moment he desires the trait, because he _can’t even reach her_. Can’t even bring her mutilated corpse into the water for a proper burial.

She’s crawled too far from the water, presumably away from her attacker. Unfortunately, the licks said attacker got in before her escape were too severe, and the stained sand beneath her tells the story of her departure due to blood loss.

Silent tears run down in rivulets to join the salt water on John’s face.

Ever the prioritizer, John steels himself. He’s got two pups below, none the wiser about the fact their mother has left this plane. He would never forgive himself if he allowed either of them to discover Mary for themselves and gaze upon her bloody body.

John says a few last words to his love, apologizing and promising they’ll meet again somewhere. He then forces himself to slip back under the water, face pale and muscles stiff with tension.

Blessedly, Dean appears to still be in Sam’s nursery. John numbly floats down to the bed of sea lettuce underneath the pool.

Having wander from place to place throughout his entire life and being arguably wild, John’s had to make a few excruciatingly tough decisions on the fly. He presses the heel of his palm firmly in his eye to stifle the tears. They won’t help bring Mary back.

John ultimately came to a decision he would occasionally regret, but it was the best option for all parties involved. There was no way he could navigate parenting successfully when it came to little Sammy, even with Dean’s help. Mary was still confusing John with her tendencies and nature up to the day she died. Even if he took a chance and raised Sam himself alongside his brother, he’d most likely be doing more damage than good. Mermaids are delicate creatures, they’re not designed to drift like sharks. Not to mention the health concerns. John is understandably unfamiliar with mer ailments. What if Sam fell sick and died abruptly when he didn’t receive the cure he needed? These are just some of the reasons that drive John to reluctantly deliver his mermaid son to the Crag colony, a place where Mary was not born but had many family friends in.

It was complete happenstance that one Bobby Singer was employed as a night guard, someone John had never met but felt as though he had through Mary’s stories.

Singer didn’t need much more information other than Sam was of Mary Campbell’s blood and needed someone to care for him. He eagerly took the pup, clearly itching to get him away from the shark even if said shark was his father.

“Call him Sam,” were John’s last words to the mermaid before he forced himself to return to the small cave he’d relocated them to that day.

Nearly as heart-wrenching as seeing his beautiful Mary’s lifeless body was trying to convince Dean that Sam never existed. John felt that was easier than telling the truth. He didn’t want Dean to lose a mother and a brother the same day. Thankfully children are forgetful and it didn’t take long for Dean to stop asking about little Sammy.

Dean became more of a quiet child after coming to terms with his mother’s death and his little brother’s apparent nonexistence. Less playful, more brutish. John fell back on old habits himself, no longer feeling the need to act more as a mermaid for Mary’s sake.

It was impossible not to wonder about Sam from time to time, but John felt in his heart that his son was doing fine and being well taken care of.

 

PRESENT DAY

Dean is not too far from him and Sam’s nest when he spots a dark figure in the distance. Hackles rising, Dean discards his precious objective of gathering dinner and swims threateningly around the figure.

Even in the dim lighting, it’s easy to tell it’s a shark. Dean’s already worried out of his mind. Is there shark territory nearby? How many sharks? Are any of them hunting Sam at this very moment?

“Dean?”

The rough, familiar voice draws Dean out of his unpleasant reverie. He stops in his tracks, brow furrowing. “Dad?”

John swims within touching distance, looking just as surprised as Dean currently feels. “Been awhile since I’ve ran into you,” his father says with a hint of a smile. John rakes his eyes over Dean’s person, silently admiring how strong and healthy his firstborn pup grew up to be.

“Yeah, small ocean,” Dean chuckles. He wants to go in for a hug—his time with Sam unfortunately making him more affectionate—but manages to wrangle the urge in. “What’re you doing out here? So close to...” Dean had asked a few times to turn to their own nest when he was far younger, each time being shot down more aggressively than the last.

Rather sheepish, John rubs the back of his head. It’s true he never aimed to return to his and Mary’s nest, but old age has turned him nostalgic. He was in the area and figured he might as well see how the cave was doing for old time’s sake. John explains as much to his son.

Dean chuckles. “Hey, no judgement here... It’s funny, I’ve actually been, uh. _Nesting_ there myself.”

“Really?”

The younger shark suddenly frowns, thinking about his mermaid mate. “Uh huh. I’m not... Alone.”

John looks even more surprised than previously. “Oh,” he breathes. “She pup yet?”

It’s Dean’s turn to rub the back of his head. “No, um... They’re... _He’s_ a mermaid, actually.” The reveal is met with silence and his father’s unblinking eyes. If sharks sweat, Dean thinks he would be pretty damn sweaty right about now. “He’s very special to me,” he adds awkwardly, worried for both his father’s heart and Sam’s health.

Eventually, John coughs. “A mermaid.”

“Yep.”

John begins to laugh abruptly. Dean thinks his father has become hysteric and simply watches him with a grimace. “That’s, ha... Wow, Dean, I mean they say ‘like father like son’ but I think this really knocks that outta the park.”

Dean frowns. “What do you mean?”

“I...” John coughs again and looks around. They both observe the impeding darkness. “There’s something I’ve not been too honest about, son.” He pauses. “Your mother wasn’t... Like us. She was a mermaid.”

The entirety of the tragic story is recounted with vague details. Truthfully, John can’t remember the specifics. And he spares Dean of the gruesome details, as well. Dean takes it much better than John expectedly, arms crossed by the end, gently rubbing his sides. “I’m sorry I had to do that to you but... I had no other choice.”

“Sam...” Dean mouths at the sand beneath them, looking extremely distress. “Where did you... Take Sam?”

“Oh...” John hums thoughtfully. “It was not far from here... I can’t think of the name.”

“Crag?” Dean offers, albeit reluctantly.

John points in agreement. “Yes, that’s it. I left him with an old friend of Mary’s... Seemed like an alright mer.”

Looking as if he’s seen a ghost, the younger shark continues. “And I bet he had a brown tail... Dark brown hair?”

“Um, yeah. Are you alright, Dean?”

Dean shakes his head, eyes wide. “I think... Dad, I think I’ve got Sam back at our nest. I need to—Fucking hell. I mated my _nestmate_. My _brother_.”

 

John and Dean return with pale faces after the latter has something akin to a panic attack. Sam is waiting in the bedroom as he usually does, given that Dean likes to deliver him food like he’s some sort of royalty.

“Sam?” Dean calls as they enter the living room, feeling like absolute shit. “Come out here.”

Sam comes out looking curious before his expression completely changes to guarded. He’s obviously anxious from the other shark in the room. “Dean?” he chirps tentatively.

Rubbing his face tiredly, Dean gestures to John. “You’re gonna have to stick with me on this, okay? This is... _Our_ father.”

John stares at Sam like he’s never seen a mermaid before. There’s no doubt in his mind that this is his baby boy. “Sam...”

“What the... What’re you talking about?”

Although he’d rather scoop Sam up into his arms and find out on what he’s missed throughout the mermaid’s life, John understands that Sam’s going to need to be convinced that he’s the son of a shark first. Not only that, but evidently Dean has nested and _mated_ with Sam. Personally, John’s not too bothered by the fact. He’s met many people who claimed to be offspring of nestmates. And there was nothing conceivably wrong with them. What John’s more concerned about is the fact Dean left Sam here alone. He’ll express that at a better time, though.

For the second time that night, John delicately recounts the tale of how Mary passed away and Sam was given away to Bobby Singer. Sam’s crying by the time the older shark’s finished. John expects accusations. He expects Sam to point a nasty finger and say ‘you left me, how could you leave me?’ He’s shocked when the crying mer swims frantically up to him, tackling him in a hug he doesn’t feel a deserves.

“Daddy,” Sam cries, holding onto John tightly. He buries his face in his father’s shoulder and continues sobbing. It seems to be in happiness, however.

John looks to Dean for help. Dean forces a smile and shrugs. “Omegas.”

**Notes for the Chapter:**

> Are people still reading this? Please comment if you enjoyed..


	8. Chapter 8

**Notes for the Chapter:**

> ah hello. basically school is ruining my life & AP classes are no joke. plz accept smut and a anticlimactic fight scene as an apology for how late this is

John spends the night, of course. And a whole week, just to catch up on everything he’s missed and become well-acquainted with Sam. The first few days the mermaid is arguably reserved, sparing his father touchy questions. Eventually Sam becomes confident and comfortable enough to breach the topic of his mother. Or, rather, return to it, because Sam doesn’t qualify the brief rundown of his childhood as substantial information. His inquisition is met with understanding on John’s part, and that last night they end up falling asleep together in the living room.

While John and Sam got to know each other, Dean remained as tense and shame-faced as it appeared the night he introduced his father to Sam. Sam finds himself briefly irritated and lonely a few occasions because of Dean’s behavior, but is quickly distracted by _dad, I have a dad._

It’s only after John finally bids them goodbye that Sam all but corners Dean, the shark insisting several times that it’s of the _upmost_ importance that he leave their nest this _very_ second.

“Dean!” Sam calls after him as the shark physically evades him. A surprise to them both is when the mermaid manages to grab Dean’s moving tail and he attempts to make a hasty exit. Sam refuses to let go, admittedly appealing to Dean’s worry of hurting him if he continues to pump his tail. “You’re acting like a pup!” he accuses.

This must upset Dean in some kind of way because he carefully turns his upper body around to face Sam. Sam instinctively releases Dean’s tail when the shark tenses his jaw and growls. “Actually, _Sam_ , I think I’m the only one having a normal reaction!” The way Dean says Sam’s name, as if deliberately not saying ‘Sammy’, further triggers some harebrained response in the mermaid. As Dean was previously—and notably literally—cornered before darting over Sam, with the shark stationary and turned back around that means Sam is now the one cornered. This, combined with Dean’s abruptly angry stance, makes Sam cower a bit. He reminds himself quickly that this is _Dean_ , though, which calms him minutely.

“I don’t think it’s very normal to avoid your mate at every cost and refuse to talk to them,” Sam huffs, irritated but not angry enough to entice a challenge from the predator.

“You’re also my nestmate!” Dean retorts. “My _brother_. What we’ve been doing isn’t normal for nestnames by any means!”

Sam rubs both of his hands over his face dramatically. “Then you’re just doing to ignore me forever, then? Spend the rest of your days slipping out of the room and leaving me all alone?” His tone fades from annoyed to sorrowful, but Dean’s dander doesn’t let up.

“What else am I supposed to do? I—We’ve fucked! And you’re my nestmate!” Dean looks hysterical, about ready to pull his own hair out. “Are you not putting the fucking pieces together? We are _related_.”

Sam rolls his eyes. “That tends to happen when people share the same mother and father.”

Laughing bitterly, Dean shakes his head. “Is this all a joke to you?”

“Of course not,” Sam responds, frowning at the shark. “I just... Don’t see why it should affect what we have together...”

Dean gaps at him. “You can’t be serious. Are you telling him that you couldn’t care less that we share the same blood?” he asks incredulously.

Sam leans tiredly against the cave wall and shakes his head. “Not completely, no. It changes... A few things.”

“A few things,” Dean parrots, still unbelieving.

“The point is that it doesn’t change that I’m still in love with you, Dean.” Sam looks meaningfully at his mate... His nestmate. “It doesn’t change the fact that I want to spend the rest of my life here. Doesn’t change how handsome I think you are or how I just want you to kiss me right now and tell me that it doesn’t change anything for you either.”

Vibrant green eyes leave Sam’s searching the ground in rapid swipes as their owner considers the mermaid’s words. “How can you be okay with this...”

Sam sighs again. “I don’t know you as a nestmate. I know you as my mate.” He cautiously swims forward and lays his hands on Dean’s chest. “I know you wanna respect your brother, Dean, but please don’t forget your mate.” His eyes burn with unshed tears.

Meeting the mermaid’s gaze, Dean swallows nervously. “I don’t wanna forget you,” he whispers as if someone will overhear them and judge.

“If being unrelated to you meant that I wouldn’t have ever met you, I... Wouldn’t want that,” Sam admits gently, rubbing his mate’s pectorals. “And it’s not... Strictly taboo. I don’t know how it is for sharks, but I’ve met mated nestmates. It might be a bit unusual in my world, but it’s not ridiculed.”

Dean croaks a small, “Really?”

With a watery smile, Sam nods. “Really. I wouldn’t let anything so dumb and circumstantial come between us like that,” he sniffles.

Reassured, the shark embraces Sam tightly and shudders. “I just feel so dirty, wanting you the way I do... Knowing...”

Sam pulls back and presses a chaste kiss to Dean’s quivering lips. “Don’t. It’s okay, Dean. I promise.” Before Dean can argue further, the young mermaid tugs him towards their bedroom—albeit that it’s been more of Sam’s bedroom, as of late, but that’s stopping _now_.

“What...” passes Dean’s lips faintly. Sam closes the distance between them and the bed on his own, enjoying the feel of his mate’s reluctance to let go of his grasp.

“Lay with me.”

Very gingerly does the shark join Sam. His posture is as if he’s swimming between spikes, tense and limited. Sam persuades him to lay once he’s close enough before rolling on top of him. Between their proximity and recent lack of intimacy, Sam can barely stop himself from mashing their lips. Thankfully, he’s able to settle for a firm peck.

Dean catches on quickly, though still tense. Sam’s hands find themselves massaging the lithe muscle between Dean’s neck and shoulders. The shark groans in appreciation.

It isn’t long before the both of them are peeking out from their sheaths. Sam pulls away from their make-out session to admire Dean’s equipment. Dean flinches when the mer wraps his warm hand around his top clasper.

“I don’t feel like a nestmate, do I?” Sam purrs coyly before confidently taking the clasper into his mouth, holding whatever isn’t engulfed with his right hand.

“Fuck, Sammy,” Dean pants out.

The top clasper throbs in Sam’s grip. Sam quite likes the sensation of power he’s getting from this position, taking more of Dean into his mouth. Once he’s gone as far as he can without gagging, the mermaid turns his focus on sucking and licking.

Encouraged by Dean’s moans and curses, Sam’s free hand encases the bottom clasper. When he starts pumping that hand—which proves difficult to synchronize with his right one—Dean writes underneath him. “S-Stop, ‘m gonna come.”

Sam, who’s resolved to continue with zeal until Dean orgasms, doesn’t stop. He’s surprised when the shark suddenly pushes him off of his claspers, clearly on the cusp of release.

“Wait, baby,” Dean sighs, gently pinning the young mer to their bed. He’s comically flushed and winded. The resulting smile from this earns him a few teasing nips from Dean. “‘S not all about me, Sammy...”

Ruthless fingers locate and pinch Sam’s unsuspecting nipples. The mermaid whimpers and squirms underneath Dean in response. The abuse fans the heat of his core, making it a pretty pleasant torture. Dean uses said abuse as an opportunity to catch his breath, prolonging the foreplay. “Such pretty, puffy titties, omega,” Dean growls. He sounds so aggressive and upset that Sam opens his previously shut eyes to catch his expression. Dean’s clenching his fangs, pupils blown from lust. A submissive whine from Sam visibility placates the predator.

“More, alpha,” Sam begs, though he feels distantly guilty for, considering the state Dean’s currently in.

“Bet you could shoot just from this,” Dean reckons, glancing down at Sam’s twitching clas—cock. “Hm, what do you think?”

A tear leaks from Sam’s right eye, unnoticeably merging with the surrounding salt water. “No, alpha, please! I n-need more...” What starts out as a loud proclamation fades into an reluctant question. Dean’s fierce gaze has disturbed Sam and made the mermaid question his capabilities.

“Don’t be greedy, sweetheart.” Dean leans down and presses wet kisses to Sam’s chest for a few heartbeats before replacing his left hand with his mouth. Sam cries out.

Left hand now jobless, it traces the indentations of Sam’s abdominal muscles lightly. With no more pressure than a strand of sea grass in the breeze, it trails from the base of Sam’s cock to the tip. Dean presses the rough callous on his thumb to the underside and rubs gently.

“Dean!” Sam sobs, now crying apparently.

Sam’s so close—steadily edging towards oblivion—when the shark’s left hand retracts. While the mermaid is busy mourning the loss, Dean removes the rest of himself. Sam regards him with betrayal and blurry vision.

“Sh.” Dean silences his desperate mate with a kiss. “I’ll care a’you, sweetheart.”

Large hands cover Sam’s pectorals again, wasting no time before attacking his undoubtably red nipples. Sam tries to use his own hands for some semblance of relief but is blocked by Dean’s elbows. Somehow both elbows manage to settle in the shallow groove of Sam’s arms, effectively pinning them.

Unlike Dean, Sam is relatively new to sex. Because of this, nearly every time they have sex the mermaid discovers something he really likes or doesn’t like at all. This encounter has already left Sam with multiple kinks to return to for further testing (e.g.: biting, orgasm denial, nipple play, and merhandling), but what happens next can only be referred to as a fetish.

Restraining the mermaid with nothing but his elbows, Dean’s mouth latches onto Sam’s jugular. The shark proceeds to snap his hips several times in hopes of his bottom clasper catching Sam’s entrance. Dean growls in frustration when this proves to be inefficient. Why Dean’s growls inspire a wave of pleasure in Sam, a mystery, but there’s little time to ponder that as the clasper finally finds purchase.

The initial penetration brings only a microsecond of pain. Any other discomfort is immediately masked by Sam’s dwelling of _he’s pinned me down like an animal, like a dolphin, breeding me like a dolphin_ —Sam all but screams in pleasure, basking in the bruising pressure on his left and right cubital fossa. From nothing but halfhearted tugs on his nipples and brutal banging against his cervix, Sam comes.

Dean follows shortly after, ejaculating warm seed deep into his mate. His hips jerk until sensitivity becomes too much.

When Dean finds the strength to pull out, they assume a more innocent embrace. Sam smiles lethargically at his mate as they hold each other, clenching around Dean’s cooling seed and cuddling closer each time he does.

 

Two moons later, on an unremarkable day at a unremarkable time, Sam is browsing a farmers market in Pandemos. Instead of asking a vendor—who will no doubt suddenly advertise their products as what he’s looking for—Sam hooks a seasoned omega with two baskets full of greens. “Excuse me, do you know if there’s anything available here that could help with nausea?”

The old mer appraises Sam before answering. She smiles with a knowing look. “There isn’t much to curb what I think you’ve found yourself with, ξένος. But don’t worry, it usually passes after the third moon.”

Truly confused, Sam furrows his brow. “Excuse me?”

“Aphrodite has gifted you,” the mer replies. “Don’t you see?”

Before Sam is able to inquire further, the older omega is pulled away by a beckoning voice and lost in the crowd. Sam is left blinking frantically, flabbergasted. Mind too muddy to correct his rude loitering, Sam’s hand presses against his lower stomach to inspect a mysterious swell.

 

Sam decides to wait another half of a lunar cycle before voicing his suspicions. By this time, the swell has expanded despite an increase in morning swims and a more calorie-conscious diet.

He feels almost silly for treating it as a shameful secret. After all, didn’t he daydream constantly about his future pups when he was no more than one himself? Wasn’t it he who trotted around Crag with a pup doll from his fifth to eighth spring, much to Bobby and Karen’s amusement? Why then is it so difficult to bring it up to Dean?

They’re cuddling together in the living room when the moment strikes Sam. He gestures to one of the empty cave veins parallel to the couch. “That was my nursery, wasn’t it?”

Dean hums into Sam’s neck, reluctant to move his head. “Mhm. Not much of a nursery, though, since it was just you.”

“It’s awfully close to the mouth,” Sam comments, referring to the cave entrance. Dean offers another lazily ‘mhm’ in response. Before the mermaid can lose the nerve, he continues. “It’s a good room for all the furniture, but I want the baby to sleep with us.”

Not a single sound permeates the water for the longest time. Dean’s entire body coils like a stressed muscle. The playful fingers that were previously combing Sam’s long hair leave in favor of gripping the couch. “Say something,” Sam whispers.

“ _Sam_.”

Dean gently moves Sam so that they’re facing each other. His mossy green eyes darting across Sam’s face, searching for any signs of a joke. When the mermaid appears genuine, Dean slowly looks down at Sam’s stomach. His hand reaches out, hovers, then slowly encases the swell. “Oh...”

As exciting as it is to see his mate blatantly ecstatic at the prospect of fatherhood, Sam can’t help but giggle. “Don’t tell me you didn’t suspect a thing. Look how fat I’m getting!”

“Bite me, Sam, this is barely anything,” comes the retort, but it’s cushioned by shock and awe. Sam laughs again, dabbling in a comeback for a second or two before closing his mouth and letting Dean enjoy caressing his bump. He supposes internally that it probably looks bigger from the angles he’s limited to than the ones Dean can indulge in. “This is... Amazing.”

Peering down at his stomach himself, Sam lays his right hand over both of Dean’s. “It caught me off guard, too,” the mermaid admits in response to Dean’s gleeful surprise. “But I have no idea why. It’s not as if we’ve been using protection or anything.”

“Protection?” Dean frowns at his mate.

“Mers sometimes use contraception methods to prevent pregnancy.” Sam has to stop himself from backtracking, knowing that his explanation is grammatically undesirable for a number of reasons but deciding it’s better to leave his statement as is because it’s doubtful Dean is familiar with the word ‘contraception’. “I’ve heard of mers inserting sea sponges and other plant life inside themselves to dissuade impregnation.”

Dean blinks dumbly. “Sammy, I love you and your nerdy brain, but can I get that in English?”

“Some mers shove stuff in their vaginas to block seed,” Sam rephrases crudely, feeling the silliest urge to somehow cover his baby’s ears.

Grimacing, Dean asks, “Why would anybody wanna do that?” Along with sounding uncomfortable, if not painful, it also defeats the entire purpose of having sex.

Sam sighs deeply. “I guess it’s an attractive concept to some mers to mate without... Mating. I personally don’t see the appeal.” The mermaid decides to leave it at that for now, knowing he could go off on an entire tangent about frivolous sex. “It doesn’t work half the time, though.”

“I didn’t think sharks could breed mers. Even after Dad came... It never crossed my mind,” Dean admits, smartly returning to their earlier topic. He rubs loving circles around the bump.

“I think that’s how I looked at it, too.” Sam leans forward and kisses Dean’s forehead. “But now we’ve got even more renovations to do.”

Dean groans dramatically, it was only recently Sam expressed he was happy with their digs. “Did you purposefully wait until you were showing just enough for me to forbid you from manual labor?”

Reaching behind himself to position a pillow at the curve of his spine, Sam reclines with a purr. “I have no idea what you’re talking about.”

 

MONTH FOUR

Sam wouldn’t trade Dean for anyone in the world, but his species continually proves to be inconvenient at best. Not only is he unable to accompany Sam to Pandemos, but each ‘who is the alpha’ question digs him into a deeper hole. Sam hates lying, even if it’s for a good reason.

“All appears well,” the colony’s healer informs, setting aside a few colorful crystals he was holding against Sam’s abdomen a moment ago. “Is there anything that concerns you?”

Embarrassed, Sam forces himself to ask, “When do you think I’ll give birth?”

Smiling kindly, the healer gently cups Sam’s baby bump. “I would say five or six moons. Return to me if you encounter abnormalities and rest easy.”

It’s only when Sam joins Dean at the statue they always use as halfway point when he realizes he doesn’t know the difference between normal and abnormal, at least when it comes to pregnancy.

Overall, the fourth month of Sam’s pregnancy is unremarkable, albeit filled with excitement and a sense of optimism for the future. His energy fluctuates from rowdy to bone-tired, but Sam’s glad to be rid of morning sickness.

 

MONTH FIVE

Sam can thank Bobby for teaching him how to budget as the reason so much treasure remains from their original find of the mysterious trunk. The mermaid no where near skimped on decorations or flattering furniture, but he definitely thought out each purchase carefully.

They’ve decided to splurge on baby furniture and cut corners on decor. Sam saw no issues with this considering it isn’t too difficult to gather organic decorations.

Sam’s protruding belly doesn’t really get in the way of collecting seashells, but it’s definitely a hard, solid weight that occasionally throws him off balance.

Admiring the symmetrical ridges on a particular seashell, Sam notices a dark spot in his peripheral. He moves the seashell out of the way and squints.

In the distance, Sam can make out some sort of mer making their way towards them. He frowns momentarily. It would have to be another mer, because while Dean might not seem like a snark from far away, Sam’s tail is unmistakeable. He loathes the idea of someone swimming away in terror at the sight of Dean. Or worse, have it be someone he knew and have news of how he went crazy and ran away with the shark that murdered his friends make it’s way to the gossip circle in Crag...

“Sam,” Dean growls, suddenly blocking out the dark shape by swimming in front of the mermaid. He scans the horizon, perhaps searching for more figures. “Stay behind me.”

Unsure if there’s any danger to truly stay away from, Sam gets up and looks over Dean’s shoulder, not unlike a shy pup. “Oh... Dean,” Sam whimpers when the figure draws closer.

It’s most certainly not a mer. Sam immediately recognizes the brown and black tail, littered with stripes. He quivers, though not remotely as bad as he would if he were caught out here by himself.

“Ahoy,” calls the tiger shark.

Dean clenches his fists, forgoing a greeting. “Mine explaining why you’re in my territory?” he projects, voice loud and threatening.

“It’s nobody’s ocean, partner,” the tiger shark replies smugly. He stops seven or eight fins away from them, swishing his tail in what Sam can only describe as a playfully dangerous manner. “Mine telling me why you’re hoggin’ that fat mer?”

Blood bursting with adrenaline, Dean puffs out his chest and gives the other shark a good look at his teeth. The tiger shark showcases his own, making Sam cower when he sees how much more thinner and unsettling they are compared to Dean’s. “Think I outta rid your lungs out instead.”

“C’mon, don’t see why we can’t share,” the tiger shark pouts. He swims closer but Dean holds his ground. His mate’s confidence in being able to protect him helps to calm Sam. “Ah. I get it. This your broodmare or somethin’?”

Dean smiles darkly. Sam isn’t facing him, but he’d bet that Dean’s eyes were blown with bloodlust in that moment. “Run.”

The tiger shark falters for a moment, not expecting that reply. It’s only this split second of hesitation that allows Dean to spring forward and attack.

Sam can barely make out the struggle. They grapple with each other for what seems like forever, but could’ve only been a few seconds. Dean gets a few bites in, but so does the tiger shark. After breaking the other’s arm, Dean’s able to pin to the seabed and finish the fight. Sam is both relieved and disgusted as he observes the red water.

Too long for comfort, Dean stays atop the now dead shark and calms himself. Sam’s never been a fighter, but it isn’t a stretch to imagine that it might take a few minutes to get yourself out of that fighting mode. He leaves him be, pretending to be occupied with seashells.

Dean rises, not looking at Sam as he takes the corpse by the wrist and begins to drag it. Sam doesn’t say anything, simply opting to silently follow his mate back to their nest.

Sam understands later, after hours of consideration. Dean’s placed the dead shark in front of their nest as a warning to others. Although disturbing, Sam can’t argue against it. Maybe it’s the one decorative piece that John was missing, one that could’ve prevented Mary from being targeted in the first place.

**Notes for the Chapter:**

> I know I don’t deserve it but.. comment? I luv you


	9. Chapter 9

**Notes for the Chapter:**

> :D this chapter is kind of just little slices of life (or a montage) tbh, but there’s some SPICY stuff at the end so I hope nobody minds the formatting

MONTH 6

The nursery is finally finished by the sixth moon of Sam’s pregnancy. It’s not _perfect_ , but the mer bites his tongue on the matter. It’d be nothing but irritating for the both of them, complaining about something so trivial. Especially since nothing really can be done about it; Pandemos has a wide variety of pup-oriented accents, but they’re unreasonably pricey.

It’s hard to remember that Sam is _wild_ now. Him and Dean don’t have jobs or a steady income. It wouldn’t be wise to purchase anything but the minimum. Sam’s always been a sucker for nice things, though, and the rest of their nest reflects that.

Nevertheless, Sam leads Dean to the nursery promptly after the shark returns from hunting to peacock.

“Whoa, Sammy. What is this?” Dean asks after a few moments of consecutive praise, referring to a strange object hanging above the crib.

“It’s a mobile. It’s supposed to help pups fall asleep.” It’s very ugly compared to the professionally crafted mobiles available in Pandemos, but Sam enjoyed making it. He admires how the seashells gently sway from the current.

Dean turns to Sam and beams. “They’re gonna love it.” He bends down and places both hands on Sam’s taut stomach.

“I still can’t believe I’m pregnant,” Sam admits after watching his mate fawn over the baby bump. “What do you think it’s going to be?”

Pressing his ear to the bump as if he can hear the pup answering Sam’s question, Dean hums. “Whatever I say, it’ll be the opposite. How about a boy?”

Sam clears his throat. “No, I mean...” He feels bad for switching to a more serious subject, consequently putting a damper on the mood, but they’re avoided this subject for too long. “What will it _be_?”

Comprehension hits Dean a few seconds later. He removes his hands and assumes a more comfortable treading position. “Ah, well.” He itches the back of his neck. “S’pose it could be either.”

“Do... Do you think there might be something wrong? Because we’re nestmates?”

Dean crosses his arms. “I don’t know.” He doesn’t know why there would be anything _physically_ wrong, only thinking of the moral dubiousness concerning the pup is a product of two nestmates, which to Dean still remains wrong and dirty in the back of his mind.

Sam isn’t about to explain the complexity of genetics, so he switches subtopics. “I-I meant to tell you about this idea I had. About their education.” Sam rubs his tummy for emphasis. He sighs at Dean’s skeptical expression. “Look, I don’t want them growing up completely... Uh—“

“Barbaric? Untamed? Say what you’re really thinking, Sam,” Dean interjects, surprisingly offended. Sam immediately frowns and shakes his head.

“Dean, you’re a shark! You grew up as you were designed for,” Sam defends himself with a more clear and confident voice. “I’m saying that if our pup is a mer, I want them to attend school in Pandemos.”

“School,” Dean responds flatly.

“When they’re old enough. Besides, it would be beneficial for them to meet other mers and see what society has to offer.” Sam huffs at Dean’s defiant glare. “But if they’re a shark, we won’t need to worry about things like that.”

Conceding, Dean swims over to the crib and peers into it as if a pup were inside. “I hate when you go to Pandemos. I worry about predators following us here,” he whispers forlornly.

Sam frowns deeply, making his way over to Dean to hug him from behind. He rests his head between the shark’s freckled shoulder blades. “We have you to protect us.”

“What if I’m not there? What if I’m out hunting and I come back to find you ripped apart? Our _pup_ ripped apart?”

Their situation is near identical to John and Mary’s. Therefore, it only makes sense to examine their mistakes and find solutions as to prevent any further tragedy. “I-I should buy a spear. I think I could—“

“Sam, as somebody who has gone after you with intent to kill, lemme say I don’t think you’re very well-equipped to defend yourself,” Dean scoffs.

“I think I’d have a different reaction if I saw something coming for my _pup_ ,” Sam returns sharply. “I wouldn’t let anything _near_ them.”

Dean feels Sam’s anger buzzing in the water like it’s a tangible energy. He believes him. “So we’ll get a spear,” the shark agrees.

“And be cautious,” Sam adds. There’s a long stretch of silence, and the mermaid reluctantly continues. “...It wouldn’t hurt to decorate our front lawn either.”

Turning around, Dean regards Sam with regret. “I’m sorry for scaring you like that.”

“Don’t be sorry. It - It’s a fantastic idea.” Sam swallows, desperately searching for a way to express his feelings towards the attack. “And you were protecting us.”

Dean’s hand absently trails up to his necklace, fiddling. He looks down. “I’ve missed...” Dean doesn’t finish, shame-filled eyes darting between Sam and the ground.

It isn’t very hard to infer as to what Dean’s missed. Sam feels uncomfortable but also sympathetic. “I... I don’t want to tell you that it’s okay, y’know? Because it isn’t, even if this is the way it’s meant to be. But I don’t wanna act like I can just _domesticate_ you either, Dean. You’re not a mer. I know that. And I’m not trying to pretend you are.”

Dean coughs. “I wouldn’t ask you to make that call.”

“Do you need to hunt mers?”

It’s a silly question. Sharks don’t need to eat mers. They could live off of sea grass, if not fish. It’s the same as how mers don’t need to go to school. It isn’t like breathing, but rather better than the alternatives. “Of course not,” Dean answers, laughing without mirth.

Sam suddenly wants to be closer to Dean, so he curls up against the shark and nuzzles his chest while arms slowly encase him. For some reason it’s easier to discuss these things in here, deep within their nest where they’re as far away from the world and Poseidon’s prying eyes as they can possibly be. “You don’t care about the mers you’ve killed, do you?” Sam doesn’t mean or say it in an accusing way. It’s a breathy statement.

“...No,” Dean answers truthfully, wondering if Sam would rather hear the bloody truth or more shiny lies. “They tasted _good_.” The shark’s voice drops several octaves on the last word, guttural and reminiscently _hungry_.

Sam shivers, but he isn’t scared. He doubts he has the capability now they’re intimate with each other. He feels so dirty for his apathetic feelings on the matter. Sam should be disgusted, horrified. But he can’t find it in himself to blame Dean. That doesn’t mean he’s ready to give Dean the green light, though.

“Do what you will,” the mer says ambiguously. He decides to leave the ball in Dean’s court. Sam could never be completely complacent in regards to murder, whether it be for food or otherwise.

Dean nods shakily and presses a quick kiss to the faded scar on Sam’s shoulder. There’s nothing left to say.

 

MONTH 7

“I’m so fat.”

Dean shakes his head in disagreement, continuing to move his hand towards scandalous areas of Sam’s tail. “You’re just filling out.”

Pulling away from his mate’s touch, Sam apologizes. “I feel too gross. Fat, greasy and gross.”

Of course Dean promptly removes his hand respectfully and gives Sam a once over. “You’re glowing,” he states. It’s true, Sam’s skin is somehow more ethereal now. He can’t tell if it’s more tan or paler than before, but something is definitely different.

Sam catches Dean’s eyes lingering on his chest. “I’m beginning to understand why some omegas wear wraps now,” the mer grumbles.

Dean chuckles, unabashedly ogling Sam’s swollen breasts. “You can’t expect me to ignore boobs, Sammy. That’s asking too much.”

As much as Sam would like to be in the mood, to be trapped under Dean and taken thoroughly, he’s been put off at the thought of sex for several days now. It hasn’t put any strain on their relationship, and Sam knows it will pass, but he feels slightly guilty. “I wish Mom was here. I have so many questions I’d like to ask her,” he sighs, prodding at his chest.

“You wish Mom were alive so you could ask her about your boobs?”

Sam rolls his eyes. “You know what I mean. I’m curious about breastfeeding a baby shark.”

Understanding Sam’s possible reservations, Dean comments, “Doubt it was very different from breastfeeding you, Sammy.”

“Hopefully.” Sam has heard his entire life as an omega the pros and cons of breastfeeding. Biting is at the forefront of his mind. A teething mer pup Sam knows he can handle, but having his natural predator suckling on his tit—one that doesn’t know any better—invites anxiety.

“Are we... Going to be having more pups?”

The mermaid looks meaningfully at Dean. “I assumed so. As long as we can manage them all properly.”

Dean is disheartened at the idea of sacrificing their intimacy in fear of conceiving more children they have no room to support. It’s a responsible mindset, but not a very fun one. “Looks like I better keep an eye out for sea sponges.”

Sam gently strikes the shark’s bicep. “You wish, jerk.” He suddenly flinches, crying out.

“What’s wrong?” Dean demands, my seeing any possible threats around.

“They’re flapping again,” Sam groans, leaning back in hopes of discouraging their pup from beating up his insides. It doesn’t work. “It’s like I have a little angry alien growing inside me.”

Putting his palm flat on Sam’s bump, Dean waits patiently for another flap. He’s rewarded a few moments later when the pup pumps their tail again. Sam hisses while the shark grins ear to ear. “Real strong.”

“Preaching to the choir here,” Sam wheezes.

 

  
MONTH 8

The era of sex-aversion ends the first day of Sam’s due month. He’s even bigger than before, but somehow feels more comfortable in his own skin despite the sharp stretch of skin around his abdomen. The only thing that’s bothering him—other than the regular worries any mother-to-be would be having—is his new stretch marks. They paint the sides of his huge belly, some parts pink, others already faded into silvery scars. Sam hates them.

Dean notices the mermaid attempting to get a good look at his stomach, reasoning Sam is curious about how big he actually is, but has doubts when he watches Sam run his hand repeatedly over the marks with a frown. “Hey.”

Flinching as if Dean didn’t live here, Sam maneuvers himself towards Dean clumsily. “You startled me.”

“Sorry, sweetheart.” Swimming up to his mate, Dean leads them both to their bed so they can sit. “Something bothering you?”

Sam blushes, looking away. “It - It’s dumb. My...” He gestures to his stomach. “I forgot about this part. How my body will be... Ruined after this.”

Dean can’t imagine any version of Sam he wouldn’t be attracted to, much less a Sam with markings that broadcast Dean’s fertility and diligence as a mate. It also shows the mermaid is spoken for, which pleases Dean. It’s the ultimate hickey. “Look at me, Sammy.” He waits until Sam is staring expectantly. “You’re beautiful. You were beautiful before this and you’re especially beautiful now, heavy with my pup... So I doubt you’ll be any less beautiful afterwards.”

Sam’s hormones are getting the better of him; he nearly cries. “You don’t think it’s ugly?” he whispers insecurely.

“Do I think the kick ass lightening bolts across your stomach are ugly? Of course not,” Dean answers casually, as if it isn’t a big deal. It really isn’t, but Sam’s acting like it is. “‘Sides, shows how I’ve done right by you.” He slowly moves his hand to cup Sam’s stomach, giving amble time for the mermaid to move away.

Watching Dean stare memorized with his stomach, Sam’s mind settles briefly before wandering to other things. “I’ve noticed what you’ve done to the spare bedroom.”

Dean hums. “I was worried you wouldn’t get to it in time. Looks like you’re gonna pop any day now.”

The mermaid rubs the leftover tears from his brown eyes, nodding. Dean’s attempt at what can only be described as a delivery room is thoughtful at best and pathetic at worst, but Sam still thanks him. “It’s going to be so strange... Not to be so heavy and clumsy anymore.”

“I’m sure you’ll still be plenty clumsy, Sammy,” Dean snorts.

Sam goes to shove Dean in retaliation and nearly toppled over. He blushes furiously and Dean laughs at him. “Jerk.”

Dean plants a good-natured kiss on his mate’s cheek for forgiveness, succeeding only as he allows Sam to wordlessly guide his mouth lower. He sucks gently on the brunette’s neck, wrapping a clammy hand around Sam’s hip.

Moaning softly, Sam unintentionally flaps his tail. “ _Dean_...”

The shark pulls back just enough to admire a steadily forming love-bruise. “Hm?” Dean’s free hand wanders to Sam’s puffy pink nipples.

Weeks without intimacy have taken a toll on the both of them, but Sam feels particularly touch-starved. Dean’s clever fingers awaken a lust in him that surely wasn’t there only moments before...

“Mmm,” the mermaid mewls, leaning into Dean’s grasp. “Alpha...” Sam’s feels his loins stir in interest, making him shiver and stretch.

Dean’s claspers—rather enthusiastically—begin to peek out within his sheath. He instinctively humps against Sam’s tail. “Look what I’ve done.” Dean unkindly pinches Sam’s nipple before slapping the mound of flesh. “How well I’ve _bred_ you.”

Sam whines pitifully, sucking on his bottom lip. He lets himself fall backward, effectively laying down on their bed, hoping Dean will follow. The shark does indeed, climbing atop his squirming mate with dark eyes.

“Swollen with my seed.” Dean stares intensively at Sam, predatory, before darting down suddenly and nipping the jut of the omega’s clavicle. He lingers after the bite, tasting no more than a microgram of blood in the surrounding sea water. “ _Fat_ and _helpless_.”

The unsavory descriptor fazes the mer no longer, instead only furthering his arousal. Sam struggles halfheartedly, provoking Dean to pin him down. A gush of slick joins the churning water around them.

Writhing underneath the shark, caught with an iron grip, Sam certainly feels helpless. Helpless and _unbearably_ horny. Although the sight is obscured by his enormous belly, Sam knows his own cock is exposed and twitching with excitement.

“I could do anything to you...” Dean purrs wistfully, squeezing Sam’s wrists as his eyes sweep over Sam’s probe form.

They’re just inches apart, and Sam’s drawn from the fogginess of his libido when he notices Dean’s striking eyes. They’re unsettlingly contracting and expanding, as if battling between the effects of bloodlust and carnal lust; as if Dean’s hormones can’t decide if it’s time for a meal or a fuck.

Sam’s bombarded with such a strong wave of arousal that he’s nauseous for a moment. Wanting simply nothing more than to chase that delicious, stimulating adrenaline, the mermaid pleas, “Don’t hurt me, p-please.”

A brief look of confusion or regret passes over Dean’s face before he realizes there’s little fear exuding from Sam, not remotely enough for him to sincerely be afraid for his life. Dean’s shoulders relax as he makes a deep rumbling noise somewhere in his chest, leaning closer. Sam closes his eyes as the shark drags his tongue across his flushed cheek. “Why?” Dean hisses. “Because... of this?” A hand drifts down to ghost over the peak of Sam’s tummy. “Because of the pup I fucked into you?”

The hand fondly rubs the sensitive marks adorning Sam’s taut skin before traveling lower. “Or _this_?” Dean cruelty grabs Sam’s weeping cock. “Because of how desperate you are for me to fill you again?”

Sam’s so desperate for friction that he doesn’t mind the uncomfortable hold. He snaps his hips, crying out when Dean lets go in favor of holding him down. “You slut. You’ll take anythin’ I give ya, huh?” When he doesn’t receive an affirmation, Dean roughly tugs on a nearby nipple. “ _Huh_?”

“Anything, alpha!” the mermaid agrees, close to tears with frustration.

Dean grins ear to ear, saliva escaping between his fangs and forming a sizable glop on the corner of his mouth. His eyes are gleaming fiendishly, making Sam gulp.

Suddenly, the world shifts dramatically as the mermaid is nearly hauled straight off the bed, only minimal traction preventing him from falling head-first onto the cave floor. “Easy, sweetheart,” the shark murmurs, as if he’s the one getting tugged around like a dolly.

Sam’s vision is filled with the confusing, upside-down image of Dean’s upper tail. White, gray, and pink hover before him restlessly. “Open.” Sam must take too long trying to orient himself, because the shark abruptly hooks his fingers around Sam’s mouth, opening the humid orifice as wide as he’s able before prodding it with his bottom clasper. “Open, bitch!”

Despite his callous words, Dean does take a minute to make sure Sam’s in prime position to penetrate, not wishing to irreparably damage his mate’s throat.

Once the shark has set a gentle rhythm, however, all bets are off. Sam focuses on keeping his throat open and trying not to gag. It’s not easy to do, but easy to focus on because his reality is now limited to the thick meat invading his mouth.

“Yeah, baby, look at you,” Dean praises, one hand wrapped around the mermaid’s throat to feel the muscles accommodate him while the other plays with the head of his top clasper. “Such a pretty little fuck hole...”

Sam moans around Dean, his cunt clenching and unclenching in need. Giving Dean head has always been a humble reward, but they’ve never done this position before, and Sam is drenched from the sensation of Dean’s top clasper rubbing greedily against his chin and straining throat. The omega can only imagine the picture he makes...

“Fuck!” Dean exclaims, and Sam is sure he’s about to get a mouthful of seed. Before the disappointment can set in, though, the shark carefully removes his clasper and backs away. Sam takes the opportunity to cough raggedly as Dean paces.

Dean helps Sam lay back down on the bed properly after he’s not at risk of spontaneously ejaculating. The mermaid doesn’t have a chance to grunt a simple ‘thanks’ before Dean’s suddenly on him again, frantic.

“Want more of my seed, baby?” the shark mumbles, looking positively feverish for someone incapable of sweating. Sam nods, dipping a few fingers inside himself before allowing them to relocate to his clit.

Slapping away Sam’s hand, Dean alines himself gracefully and slides in to the hilt. Sam screams in pleasure, wrapping his arms around the shark’s back. Dean wastes no time to begin pumping his hips brutally, having difficulty finding Sam’s cock without looking because of the unfamiliar mass almost blanketing it.

They last no longer than a few minutes like this, going at it mindlessly. No worries, no anxiety, just the _squelch, squelch, squelch_ of Dean’s clasper driving into Sam’s pussy without mercy until climax.

**Notes for the Chapter:**

> next chapter will be the last ;( but don’t cry! You’ll get to meet their baby! A boy? A girl? A shark? A mer? Whooooo knows ;) anyway. please comment!!! it guilts me into updating & also makes me feel fulfilled


	10. Chapter 10

**Summary for the Chapter:**

> Sam and Dean’s love has manifested into a undecidedly graphic birth scene.

**Notes for the Chapter:**

> I’m planning on adding a extra “chapter” of sorts with baby shenanigans. If that’s something anyone is interested in :D
> 
> sorry this took long + there’s probs grammar mistakes cuz I just cranked this out <3 thank you for sticking w/ me thru this journey, I’m pretty proud of this story

MONTH 9

Something Sam never considered, being among more serious problems (e.g. the pup’s species, educational future, and diet) as it were, was house-arrest. Or _body_ -arrest. Self-induced imprisonment by Sam’s very own spawn.

The ninth moon marks Sam for an upcoming delivery, which means he’s _ginormous_. Sam’s seen pregnant omegas before! Touched their belly and the like. But it’s a whole different perspective, being the one carrying around what feels like a premature whale. Still, Sam’s sure he’s somehow managed to conceive the fattest pup in oral tradition.

Thus, being so ginormous, Sam’s found it uncomfortable to swim. This means minimal movement throughout the day, having Dean assist him from room-to-room in their grotto. Sam spends most of his days in the living room, basking under the sunlight and soaking up the rays. He’s sure he’s gained more than baby fat from this laziness.

But there’s more to this pressing issue than simple boredom. Sam could cope with that, he’s made it this far after all, and doesn’t have much further to go. But the lack of things to do combined with the lack of people to see has worn him down mentally. Sam’s never considered himself much of an extrovert, but the past months have been shockingly lonely.

Shouldn’t Dean be enough? Why is Sam so disheartened? It isn’t as if the mermaid misses specific people (not unbearably, anyway) but just everyday interaction itself. Sam misses Crag; he misses waving to his neighbor’s every morning and gossiping with his friends; he misses the marketplace food and learning new things...

Sam feels a pain so sharp and cold it’s as if ice is crystalizing on his heart. Is this really what he wants? All there is? Surely there’s more in store for the future. Surely more Dean has yet to show and him. Surely...

•••

Dean is more observant than he gives himself credit for. It only takes a few days for him to question Sam’s recent sadness.

“Do we need to talk about something?” the shark asks reluctantly, expression more commonly found on someone having their teeth pulled.

“Mm.” Sam’s staring up through their skylight, watching the underwater ripple of stars dance above them. “I’ve just been thinking lately...”

“Uh-oh. That’s never good,” Dean comments playfully, already trying to lighten the mood before he even knows the depth of the problem he’d rather avoid.

Ignoring his mate’s remark, Sam rests a hand on his belly and sighs deeply. “Dean. I don’t want you to think I’m unhappy with you.” He looks carefully at the shark, holding back a giggle when he’s meet by Dean’s suddenly pensive, pale face. “But there are logistics popping up that... Are bothering me.”

Dean swallows. It’s clear he’s thinking the worst despite Sam’s statement. The shark scoots closer and takes Sam’s free hand into both of his, silent. It’s all Sam needs to continue softly, “I don’t want to spend my life in a cave, Dean. I want to travel—see new things, meet new people. I want... _Friends_. A j-job, maybe...” Sam looks away with a flushed face, unable to hold eye contact any longer. “I thought originally that I could adjust to this lifestyle with you, _for_ you, but... I don’t think it’s good for me. And if we have a mer, I know it won’t be good for them.”

There’s a long stretch of silence. Eventually, Dean squeezes Sam’s hands. “I can’t give that to you,” he whispers in the moon-lit cave. “Damn, Sammy, I wish I could, but... I thought you knew coming into this what you were getting.”

Dean’s hands begin to pull away, and the mer hurries to recapture them. “I knew, Dean. I knew. But there’s adjustments we can make. Middle ground.”

Not so much holding Sam’s hands as allowing his own to be cradled, Dean snorts humorlessly. “Middle ground. You realize... This cave, our home? Staying here with you? This _is_ middle ground.”

Sam blinks in confusion for a moment before he audibly gasps with realization. Here Sam has been, pitying himself, when Dean has been making the same sacrifices. How could he be so ignorant? “Then you know what I mean, don’t you?” Sam waits for the shark to look him in the eyes. “You’re right there, too. Conflicted. Your instincts are pulling you one way while your heart pulls another.”

“Okay, no need to go all philosophical—“

“The _point_ is... We have some changes to make. Changes that better both of us.”

Dean looks more amenable now. Sam hopes that Dean’s obvious thought that his own benefit would never be considered was somehow ingrained from childhood, rather than expected from his mateship with Sam. The last thing Sam wants to be perceived as is unapproachable or unreasonable.

Knowing a vague question such as ‘what do you want’ or even ‘what have I been denying you’ will cause Dean to clam up, Sam takes a moment to critically deduce what could be bothering his mate.

Intertwining their fingers, the mer sighs. “We’ve put each other in very strange positions.”

“That’s putting it lightly. If only you were an octopus,” Dean jokes, referring to the fact octo-mers are typically ostracized and morally ambiguous (and bitter) because of it.

“If only,” Sam rolls his eyes. “Unfortunately we’re stuck like this. So we’ve got to find a healthy way to make this work.”

Nodding minutely, the shark looks down at Sam’s impressive baby bump. “What do you suggest?”

Sam’s resolve wavers. He blames it on his pregnancy hormones for being so emotional. “I—I don’t... Oh, Poseidon.” The mer pulls away from Dean to cup his face. “This is unfair. So dumb and unfair. We shouldn’t have to navigate our lives around society like this!”

Dean sighs. “Yeah, you say that, but I don’t see you getting cozy with any other sharks in the future,” he responds, knowing that their relationship is an anomaly. “I know you wanna parade me around as arm candy but you can’t have your kelp and eat it too, Sammy.”

“So outside our nest, I’m meant to act as if you don’t exist?” Sam sniffles.

Reaching out and rubbing his mate’s shuttering shoulders, Dean answers, “You gotta act within the boundaries of the situation. Who knows? I’ve heard of unmapped colonies that operate outside the norms. Small population allows that.”

Sam sighs wetly. “Would you even be interested in that? Domestication?“

Dean doesn’t say a word for a long time. Sam eventually wipes his eyes and looks over to his mate. The shark appears strangely bashful. “Y’know... I’d always thought sharks were loners. That we’re too volatile to function properly in any sort of society. But... Maybe we could, we’ve just never had the chance...?” He sounds like a pup, optimistically unsure of himself.

All at once Sam feels guilty again for undermining not only Dean, but his entire species. “We can go find that chance, Dean. Me and you,” the mer promises.

Smiling softly, the shark lets a hand fall to Sam’s stomach. “You, me, and this little guy,” Dean agrees.

Their pup chooses that moment to collide with Sam’s badder. “ _Little_ —“ he wheezes.

•••

Of course, Sam and Dean decide to look into the possibility of relocation _after_ the birth. Sam isn’t about to unintentionally satirize a biblical classic by hauling himself around, looking for a place to spend the night.

They don’t wait much longer after this decision, however. Only a few hours later does Sam start to feel... Unwell. More crampy and uncomfortable than usual.

“Do yu wa’ me t’rub er ‘in?” Dean offers, barely intelligible as he forms his words around a well-chewed bone.

Sam frowns harder, giving into the urge to put pressure on his genitals. “No.” If the mer could properly focus, he’d notice Dean pushing his dinner aside rather abruptly.

Sam’s alpha, Sam’s wonderful, intuitive alpha—“Nursery?”

The realization either hits or the denial is snuffed, Sam can’t tell which. With a grimacing red face, the omega looks at Dean. “Uh,” he grunts.

Dean moves quickly, hands reaching out to grab hold of Sam before stopping. He gently touches his mate, looking at Sam strangely. “Can you move?”

Sam whines as a strong wave of pain passes through his abdominal all the way to his tail. “Uh,” he repeats with some semblance of a nod. Just as Dean’s lifting him, the shark smells blood in the water. He looks down and watches an ugly fluid lead from between Sam’s slim fingers—red and yellow and gross. For his mate’s sake, Dean doesn’t comment.

In the nursery, Dean offers virtually no help. He’s supportive, but not a medic. Sam goes between screaming at Dean for doing this to him to begging for the pain to stop to just plain screaming. Dean looks like he wants to scream, too.

“Why why why why AHH guhhA,” is Sam’s current stream of babble. His hands are frantically from the bed to his stomach, tail twitching in a visibly cringing way.

 _Poseidon, Oh. It must have been hours since this started._ Sam takes a few deep breaths and blinks teary-eyed at his alpha. “Where is it whereisit?” he demands.

Dean, perched at the end of the bed, has been watching from the best seat in the house. He has a regrettably full-frontal view of Sam’s vagina seizing and struggling. “I can see something, Sammy, you gotta push.” Omegas are made for this, but... Looking at the sad small hole clench and unclench with every painful huff Sam gives makes it seem impossible. There’s no way.

Sam grips the sides of the bed hard, pushing.

_Pushing. Pushing. Scream. Push. More, Sammy. Push! I see them!_

A huge weight is realized suddenly as something slides unceremoniously out of him. Dean swoops in to retrieve the baby and examine it.

Youthful cries soon belt over Sam’s heavy breathing. The mer tries so hard to look, but he’s exhausted, and the momentary relief is gone. The pain is back and burning and pulsating.

“Oh, wow, oh— _oh_. Sammy.”

Sam can’t concentrate on anything but the pain. The instinct to push remains. There’s an afterbirth, right? That’s probably what’s happening.

“Sam?” Dean’s talking so quiet now Sam can’t hear him over his own cries.

 _Pushing. Push. Get it out. Get out of me. Pushing. Scream. Push! Please, oh, please stop!_ Sam relishes in his own self-pity, but later he’ll think he gets a pass for it considering the circumstances.

Another huge thing escapes Sam’s channel, and with it comes more momentary relief. It’s over. It _has_ to be over. Sam can’t keep his eyes open. He can’t anymore.

“Sam!”

Drowsily Sam groans. _No, no. Dean let me sleep. I can’t._ He falls asleep fitfully.

  
•••

Sam wakes up to the sound of crying. Crying pups.

Pup _s_?

“Sam, you _really_ need to wake up,” Dean can be heard, nearly whining, from somewhere close by. Sam rubs his eyes and hisses when the movement stretches his sore muscles. “Please, sweetheart—I’m sorry, I don’t know.”

With every last bit of his regenerated strength, Sam opens his eyes. Once they’ve adjusted to the dim light, Sam realizes two things: he’s still in the nursery, and Dean appears to be codling two pups, one in either arm.

“De,” Sam whispers, somehow catching the shark’s attention over the cries. They’re beautiful, even though he can’t make out too much in the dark. “Give.”

“Here, honey, let’s go to your momma.” Dean is all too happy to unload one of the squirming pups. Whether it be Freudian or not, the shark hands over the mer pup.

The little pup settles down almost immediately in her mother’s arms, little mouth searching for a nipple to latch on to. Sam helps her, stroking the insanely soft fuzz on her head. “Hi.”

She’s such a beautiful girl—her hair appears to be a lighter shade of brown, lighter than Dean’s, but will ultimately darken with age. She does seem to be strangely skinny for a newborn, though. Sam can’t wait until morning when he can get a better look at her.

“Sammy?” The mer looks up at Dean. Dean’s eyes are sunken and red-tinged. “I need to get this little guy some food.”

Sam looks at the mer in Dean’s arms in confusion, squinting. It’s only getting darker as the minutes pass. “Huh?” he hums, to the affect of _just hand him over to breastfeed, dumbass._

“He’s. Uh,” Dean coughs, coming closer. “He’s a shark, Sam.”

There’s a moment of disbelief, but the reality sets in when the pup is brought closer. Somehow much fatter than his big (little? Sam will have to ask Dean later) sister, the pup sports a chubby grey fin. Sam is disappointed, but only for a second. That tiny sad face cannot be overlooked. “He’s so fat.”

Dean is protectively holding the presumably hungry pup, looking down at him. Sam understands suddenly: Dean couldn’t leave the nest with Sam unconscious, therefore their son has had no food to snack on.

“I think he ate your birth sack,” Dean comments, tiredly tickling the shark pup’s belly. Sam looks over their fat little son and suckling daughter and has to agree.

“Please let it be tuna or oysters. Something simple and close.”

“Of course, of course,” Dean replies, looking every bit a new father as he cradles their son. “I couldn’t—When you were...”

“Yeah. Thank you. We’ll wait here. Me and um.” Dean looks at Sam expectantly. “Mary.”

The shark chuckles, leaning down to kiss Sam’s forehead, then Mary’s. “And I’ll go get Bobbyjohn something to eat, okay?” Sam sniffles in joy.

How could he have ever doubted the success of this family?

**Notes for the Chapter:**

> So? What’d you think over all? I’d love to read some random headcanons for this AU. That’d make my year <3 <3

**Author's Note:**

> Did you like it? Please let me know in the comments below.


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